A downloadable Worldbuilding tool for Windows

Download NowName your own price

Nebulous is a desktop application designed for Worldbuilding!

Connect Ideas & Organize Projects

Creatives | Writers | Artists  | GMs

Nebulous automatically creates a nexus of ideas through which you can visualize and navigate your universe.

  • Universe
    • Create objects and build a complex categorical structure
    • Collectively manage objects with Universal tools
    • Apply Tag based filters 
  • Objects
    • Select a predefined Element collection template (Default, Character, Species, Class, Skill, Spell, Location...); or
    • Create your own Custom templates
    • Apply Advanced Text Formatting
    • Collectively manage elements with Object tools
    • Add Tags for universal filtering
    • Add Synonyms to guide the HyperNexus calculation
    • Hide contents with password protection
    • Try the Name generator and adaptive spellchecking
    • Visually customize objects and set the mood
  • HyperNexus
    • Auto-generate Wiki-like contents
    • Navigate the nexus of objects with hyperlinks
  • Nebulograph
    • Graph the connectivity map of objects
    • Visualize and traverse the idea space
  • Settings
    • Personalize the UI with flexible options
    • Export & Import settings
  • Import
    • Jumpstart your adventure by Importing from a worksheet!
    • Experiment with Nebulous and Cthulhu Mythos (Credits) Universes
  • Export
    • Transfer objects to other projects
    • Generate Text, Excel or Word reports
    • Compile your works into a ready-to-publish book!
  • Compare
    • Find the differences between two Universes 
  • Discover
    • Feeling stuck? Perform a random image search on the web
  • Help
    • Detailed guidance is provided in the Info bar

Finally, thank you kind strangers for all your support!

Soydan Yalçın

Nebulous Interactive on Itch.io, Copyright © 2020

Updated 27 days ago
Rated 4.9 out of 5 stars
(39 total ratings)
AuthorNebulous Interactive
TagsCreative, development, worldbuilding, writing


Download NowName your own price

Click download now to get access to the following files:

Nebulous v4.exe 22 MB
Nebulous v3.4.1.exe 4 MB
Nebulous Universe Sample (v4).neb 285 kB
Cthulhu Mythos Universe Sample (v4).neb 378 kB
Nebulous Universe Sample (v4).xlsx 16 kB
Cthulhu Mythos Universe Sample (v4).xlsx 36 kB

Development log

View all posts


Log in with itch.io to leave a comment.

Viewing most recent comments 1 to 40 of 46 · Next page · Last page

Thanks a lot You just save me a lot of time GMTFT :/

I find it a bit hard to organize my text and image elements. Dragging and dropping them into the desired order feels clunky and inconsistent (unless I'm missing something).

I found the way the 'static' gallery used to work in previous versions to be better in that regard, when it was always locked on the left side of the page.



Nothing wrong with the software as far as my experience has gone, just curious. Are sound and media elements not implemented yet as a feature or am I missing something to gain access to it? I am an sfx and track designer and would love to be able to put custom audio for certain tidbits.

Working with it isn't seamless however when starting, you do need to find your way around certain functions as a beginner so i'd highly recommend putting a manual somewhere in settings or making a visual guide somewhere as not everyone (like myself) ends up hovering over everything immediately to see what it does.

That aside I absolutely adore this software. I've only used it for about 3 to 4 days now as I've recently discovered it and I think accomplishes its idea really really well! Working with it is fun and I've gotten some of my friends to download it to work together with it!


Hey Maizzz!

Sound/media elements are currently not available. It's not too hard to implement but I've been taking my sweet time working on my own lore for a while now. I'll eventually get to it tho, initially I intended for the sound elements to establish a mood when viewing an object (especially for DMs), but an SFX artist wants to manage their work here too!? Awesome

Thank you!

Hi! This seems like really cool application for worldbuilding, but I was wondering if there was a tutorial on how to use it somewhere? 
I'm just struggling a little while trying to figure it out on my own lol.

Hey! Not yet, I figured it was pretty straightforward to discover and skipped on creating a tutorial but maybe I should. Many users are asking about it

If you ever do make a tutorial, could you let me know? I'll continue trying to figure it out myself, but a tutorial is always welcome lol.

(1 edit)

Recently downloaded v4 after using 3.3 for a while and v4 flatout refuses to run. No dialog or anything, just won't launch. running on windows 10

Hey kektus, 

Interesting... Do you have any crash report in C:\Users\your user name\Documents\Nebulous Crash Saves ?

nope, nothing there

So, I have no idea what the cause of this is but I literally cannot operate things that require moving to the right of a context menu. Trying to move the mouse to the extra options always cancels the menu.

Hey Swoonet!

How about now? 

Can you please try with Nebulous v4 Test (18.2.2024).exe

(2 edits)

Didn't change anything for me, also attached a photo to try and show what I mean. Trying to move between the menu gap just closes the extra menu. It does this for all other cases as well. Additionally, loading up an existing universe from an old version it seems like if an entry had a photo linked to it, the program hangs trying to load that for some reason. Lastly, again don't know if its a unique issue to me for whatever reason but the actual neb files don't seem to be visible in the folders they are saved to.

Alright, let's try once more (I forgot to change "StaysOpenOnClick = True" for the main MenuItem style before), fingers crossed now.

Also stopped refreshing all properties of the object when tab selection changed, this may help with halting as it will only try to load an image once (I hope)

(1 edit)

Didn't work for me still, and for example with the table columns options it does this as well. The photo update did work though. Tried changing mouse cursor size and it doesn't alter anything either.

That's one down at least :)

OK, one last push tonight, I added "StaysOpen=True" for the ContextMenu of elements. This hopefully will help (might need to close that little gap if this doesnt work out)

Hey, I've run into a strange problem. Whenever I custom resize something and get all of my elements correctly placed, if I close out of it or go into a different category then come back, all the elements will change their sizes and position themselves randomly. I'm not sure why this happens or if it's intentional or not, as it messes up my formatting and I cannot keep things how I want them. Lmk if I'm missing something here or if you can help.

Hmm, I cannot locally reproduce the problem. It should really remember the element sizes...

Are you in the Column or Freesize mode? Maybe I can force it to update one more time after the controls are loaded

I am in freesize mode. Another weird thing is that if the issue happens, when I resize another object, it fixes itself and remembers the size I set it at. Updating it a second time might fix this since it seems to know the correct size but doesn't want to display it until an element updates.

Here's a video of the issue with some sample descriptions and images and text. In the first part, you can see how I have everything sized up and formatted how I want it. Then I click into a new tab and then back into the original tab. When I'm back in the original tab, all of the sizes and positions have been messed up from how I had them before. And then once I resize a random element, the sizes and positions remember how they were meant to be and fix themselves.

Ohh this explains is, yeah I think maybe a delayed update could fix it. Let me try a couple of things, I'll get back to you

Also love that S.I.L.L.Y. monster!

(1 edit)


I uploaded Nebulous v4 Test (17.2.2024), now everytime the tab is changed all the bindings are refreshed. I hope this resolves it!

Could you please test it out and let me know?

(1 edit) (-1)

The download is being blocked because defender claims there is a wactac trojan in the file. I will not be downloading this or testing it until I am sure the program is safe. This didn't happen with previous versions so I am unsure what happened.

Hey Eric, I researched the issue on stackoverflow and tried to apply some of the suggestions. How about now?

Avast clears it for me.

A really nice software you've made here, all of the text and object options work perfectly for what I need. I appreciate the short keybinds like ctrl+enter to quickly update things as well as needing to press control to move things around so I can't accidentally mess anything up. The open/close all items is also a nice QoL addition as things can get overwhelming with a ton of tabs open.

Although I wish you could manually sort out the Nebulograph tree to connect what I want. I understand how it sorts things based on how many times they are referenced, but it's difficult to get things in a particular order when you have a lot of objects and they decay from the graph no matter what I try. Additionally, even just opening the graph with only about 25 objects freezes the program completely because of how it has to sort through with the algorithm. It would be nice to add an option to use manual tree making instead where you can move around objects, include and exclude certain things, and connect them however you want.

I would also love to see some kind of guide document or video published on each update to showcase all the current and new features of the program to help out beginners or show current users what's new. Starting off, the program did feel very clunky and it was difficult to navigate all of the different features, not knowing what each did, especially in the Nebulograph. The mini descriptions when you hover over something do help, but a longer form guide would be better for beginners.

All of this being said, everything else in your program runs perfectly and this is exactly the tool I was looking for for my worlds. I hope to see the continued improvement of the software and look forward to updates!

Hey Eric!

Wew, thank you for the detailed review. I was thinking of an index based sorting option for the tree which you could easily rearrange, but I thought that kinda defeats the purpose of having a hierarchial tree structure. Maybe I should reconsider.

And yeah, when there is a large number of objects, the linking takes a couple of seconds (I tested with my own library of 4000+ objects), but that's Regex for ya :(

It is in my notes to add a guidance document, maybe even make videos as you suggested too

Again thank you, it makes me happy that people actually use the program!

Saw a couple of other comments about the program, and I just want to say that it's safe to use. Windows freaks out about it, but it freaks about any program where it doesn't recognize the publisher. Looking at task manager when it runs doesn't show anything untoward. No unexplained resource usage or similarly named windows apps taking more resources than they need. Additionally, Malwarebytes says it's clean, and that's good enough for me.

That said, this is a wonderful tool that's made fleshing out my stories a lot easier compared to other world building and writing tools. I have a few stories going at once that take place in the same town, and with the graph I get to see clearly how everything relates together. A nice touch is the option to exclude certain objects from the graph so they don't clutter it up. Plus, with everything interlinking through keywords, if I'm unsure about a detail I can't quite remember, it's just a click away. In say scrivener, I'd have to dig through my file sections, since I end up way more cluttered in it than I do in nebulous.

I will say, it is a smidge clunky feeling at first, since it took a moment to get used to creating objects to act as the over arching categories to nest new objects inside. Once you get used to that though, working in it is a breeze. It's making writing for my game easier since the way I use it works well with how I think, easily hopping from one section to the next, adding bits and pieces as I go. It's like super organized sticky notes.

My only request (if it isn't in the program already) is to have the writing fields be in dark mode too. Hurts my eyes a bit when I have to edit or add objects, and it's a flash of white from the text fields when I open them up. I know there's an option for changing themes in nebulous, so if there's an option for that to make the text field dark, I haven't found it yet. ; w ;


Wow, thanks for such a detailed review!

The dark editing mode currently doesn't exist but it should be pretty easy to implement, I'll look into it and let you know.

You're welcome and thank you! Hopefully it can be easily added, since it would improve the general usage for those of us with sensitive eyes. ; w ;

(1 edit) (+1)

Yo! I added Nebulous v4_Test.exe, can you test it out and let me know?

Turning on Settings > General > Adaptive Mode adds Universe BG Color on top of Content BG Color at 50% opacity. 

I hope this is an acceptable solution (I didn't wanna add a whole new color property for this)

(1 edit)

It's a perfect solution. My eyes and I thank you so very much. ; w ; 

Very sad that my PC nukes this the second it finishes downloading, I was looking forward to trying it out. It specifically marks this file as a trojan, which isn't very inviting ngl... I've never had this issue with another itch.io executable before either so I'm not sure what is up.

Which antivirus? Maybe I can test and perhaps appeal to them 

New update is being read as a virus threat by Windows Defender

I dunno what I can do against that :(

I think they tend to block every unfamiliar executable...

Although Avast clears it!

(2 edits)

Just started using this and it seems pretty nice but I've run in to apparently an error. Not sure if this is just on my end for whatever reason but creating anything besides a default entry under a category seems to lock the new object as using the exact same display name as the category it was made under no matter what you change it to.

Also, moving objects to different categories does not appear to automatically alter the listed category. I tried this and ended up somehow with a character that links back to itself too.

Hey swoonet,

You're not using v3.4.1 by any chance, are you?

v4 allows you to pick arbitrary names and categories indeoendent of your hierarchy. Could you send an example of the issue please?

It says v4. As an example say you create a default category for people living in a village called Red village. I create a new entry under red village and set it to character and name them then hit save everything. No matter what, the displayed entry remains being called red village even if the name when you double click is correct, it stays with the wrong name in the column. It does this for me on every option unless you save it as default then go back and change it to character or w/e.

Interesting, if I'm not misunderstanding I can't reproduce the issue.

(1 edit) (+1)

I got it to stop doing it, seems to be a bug as it fixed itself after I went and changed the category of the default object/category I was creating the new objects under to nothing then changed it back.

That's good, pheww


What does this do that Trillium Notes doesn't? I only discovered Trillium recently, and both this and that look awesome.



Honestly Trilium looks awesome! I wasn't aware of such a program when i first started coding  (ಠ_ಠ)

Nebulous would be a simpler alternative, with couple of different features (like the auto wiki generation, reporting options etc as far as I can tell)


This tool is cool to use, but I wish there was a way to edit the connections on the nebulograph directly to make it where its not a struggle to figure out why things arent connecting.


Hey Voltt,

The graphing algorithm connects the objects based on the count of overlapping words in their contents (with a higher linear weight on intersecting names), and the spread is limited by an arbitrary number (otherwise it can get quite complicated and slow). I think increasing the spread and decreasing the decay may help you include more objects. Also, perhaps including the precise terms you want to connect in Synonyms could work as well!


you are incredible <3


This is a really impressive tool, but there's some functionality that'd be incredibly useful to me concerning object categorization, so I hope you don't mind me leaving a feature request:

The first feature that would be super useful would be the ability to somehow compartmentalize objects of the same category.

The second, admittedly more involved feature, but one that I think would be really powerful would be the ability to place objects in multiple categories

I realize you can kind of approximate some of this of functionality using properties, but it'd really useful to, for example, quickly get a list of all Underworld Deities without having to open up graph view, categorize all of them exclusively as Underworld Deities or personally maintain a list.

I appreciate this kind of functionality may well be no small task to implement, so I understand if this outside the scope of this project, but I wanted to leave a comment all the same. Thank you for all your hard work!


Hey rufia,

I just added a Clone function to the new version. I think this could help with your 2nd request (although both have to be maintained separately). I cannot reuse the same object because that messes up with the selection processes ;_;

For the first one, I added a Tags filtering option. This would -I think- may answer your request.



Thanks for the quick response! I think tag filtering might be a good alternative for what I'm looking for - I look forward to seeing the next version!

(2 edits) (+1)

Thank you very much for this tool. I really appriciate your effort.

I have encountered 2 bugs. I will try to discribe them.

1. When you double click on one picture from the right column and make it show only the clicked one, if you remove it, the picture column becomes blank and you can't access the other pictures that you have added in the object. Only way to fix it is to delete the object and make it again.

2. When I try to change the size of the picture from the column slider sometimes the tool crashes.

I would like to make a request too for a future update. I would appreciate it if you could make it to accept other languages too (like Greek). I think you will have to change your encoding to utf-8.

Hey DrazorV,

Thanks for the feedback! I'll try to incorporate it into the next version!

This software has really helped me and my better half bring the planet of Taenjaar to life, and I am truly grateful.

When can we expect the next update, if any planned? 


Hey Kenni, happy to hear that!

I have been working on new features but my day job has been crazy busy... Hopefully, I can release an update soon!




Hi, really enjoying using this for keeping track of my little worlds! I am seeing a weird behaviour, maybe a bug? When I ctrl click on a section to make a new object in that section, it opens three new object tabs at once. The action when hitting the new object button is normal, it's just when creating a new object within a section.

Not app breaking or anything but a tad annoying.

Nice catch! I believe it is due to the click counting each level of the treeview... I'll see what I can do 

The current save system effectively works as "save as" button. Is it really so hard to make it remember the name of the file and just use it when saving second time and onwards?


It is an intentional design choice to prevent accidental data loss by overwriting your old save files. But I will try to make an option for this in the next iteration.

Also saving crashes under Documents makes sense.


I have been looking for something exactly like your software for such an excruciatingly long time now! It really does exactly what is needed for world building. Thank you so much for this :)

One small thing, and maybe it's just me suffering from data loss, but it would be absolutely awesome if there was a shortcut to quickly save, simply overwriting the currently open file without a save dialog.

An optional autosave after Generate would of course be the cherry on top of the cupcake *haha*

Keep up the good work, you're always awesome *thumbs up*


Glad you like it!

In case of a crash, Nebulous should save an up-to-date copy of your universe to your desktop. But, I'll look into a periodic saving option in the next version.


Ingenious that the universe is automatically saved to the desktop in case of a crash. I did not know that *haha*

Thanks a lot for your efforts. Have a great time!


Great, so it will clutter my desktop. Isn't it better for the program to make a backup directory under Documents like Documents/NebulousBackup, rather than to clutter people's pristine desktops?

How do you export a file from this software?

I downloaded it a couple weeks ago and started writing something up, but then lost my work when I restarted my computer. Far as I've seen the toolbar only has an "import" option.

Only when your universe have non-zero objects, you will unlock export options - to Word, Excel oe plain text 

Thank you for the help, and I've really enjoyed it so far!


Short question, i try to run the software in wine on Linux but since .NET is kind of a issue there, i only have a empty screen.

Is there the possibility of a Linux Native port in the future? If not also not a big issue. I will in the near future install a Win7 machine as a VM. So i can use that for my work on the project.


Well, I'm using WPF (Windows Presentation Foundation), so unfortunately Linux is unlikely at the moment. I'm working on a big update though, it might worth converting to Windows.

Your program looks great! I have a small question, but what is the private policy/is our data our own for your program? Sorry if this is a silly to ask, but was curious! 

I love the layout and theme for the design. Thank you for making this!

Glad you like it!

Yes, privacy is the whole point of Nebulous. As you might know there are more advanced online alternative apps but I too did not want to host my data on somebody else's servers. In Nebulous your library (essentially a save file) is located in your own PC and it works offline. 

Thank you for the quick reply, and that is a huge relief! I'm excited to play around with it!

(1 edit) (+2)

I just got this tool, but it seems great! I think maybe there should be a dropdown in the category section with presets or something, just to get the ball rolling. Heaven knows once I have to think of what to talk about without any prompts it all just fizzles out!

Small bug, if a synonym is mentioned in the object that it's a synonym of, it creates a link that causes an error.

An error occurred while calling object: System.NullReferenceException: Object reference not set to an instance of an object. at Nebulous_v3._0.MainWindow.CallObject(NebObject obj)

Ouch, thanks I'll look into it!

I was wondering, is there any way to exclude a link within the text of an article itself? Something like surrounding it with brackets like <this> or something. If not I feel like that would be something very useful to include. Something else that would be useful is a drop down menu of already existing categories when typing in a new category, so you only have to type in the first few letters and don't have to worry about misspelling it.

Also, do you have a Discord server for this program?


Hey bees!

When creating or editing an object, if you right click the Category textbox, you may choose from existing categoies.

For the other issue, I suppose we have the "Exclude" and "Scrap pile" options. For objects you do not want to link, you can exclude them by the checkbox, or simply define your arbitrary terms / phrases in settings.

Also, no discord server I'm afraid. Although do not hesitate to come up with suggestions!

(2 edits)

My issue with the current exclude option is that sometimes there are cases when you wanna link to a page in certain contexts but not others. Like how Wikipedia will link to a page the first time it's mentioned in another page but not subsequent mentions. Or like a list where you want every item to be a link but don't want to have casual mentions of list items to link to pages. 

As for suggestions, some sort of tagging system would be amazing since stuff can often technically fit into more than one category and tags would be a good way to handle that. A way of exporting worlds to html or pdf would also be great.

Also I haven't seen the existing categories pop up when I clock on the category textbox. Might be a glitch?

Edit: Oh shit I didn't see the part about needing to right click never mind. 


Hm, I'll experiment with the tagging aspect, the universe then can be filtered according to the assigned tags.

Also, for now you could perhaps use the text export > convert to pdf.

Hi! Another suggestion if you don't mind! Would it be possible to implement a way to quickly move objects around in categories, such as by drag and dropping an object into a desired category/object?

It's a bit of a hassle to reclassify objects at the moment if you change a category's name.

You can now drag & drop objects into each other! I had to avoid a few cases but otherwise I think it works quite nicely

Although sometimes it may require an F5 to refresh the display for larger libraries

Great stuff once again, thanks! :)

Great tool, been using it for some time now. Thank you for making it!

A small suggestion, would it be possible to add a feature where you can rightclick a category for example, to automatically make a new object in it? This would make it a bit easier to flesh out categories quickly, so you don't have to enter the category every time you make a new object.

Glad you like it!

Directly right clicking might be a problem (as it is a common misclick), but I think Ctrl+Click could work.  I'll get right on it!


Great solution! Thank you so much!

Been using this a bit and its pretty good.

Every now and then I'll try to assign an image to an object and it just wont work. I've tried restarting the app and using a different image but I can't get it to work.

Also I've found that when I got to select an image i have to change it so it searches for all files not just the selected ones because the images don't show up otherwise.

Are these known issues or is it just me?

Hey MrSnowman!

Interesting issue... I suspect it has something to do with WPF not notifying the change to the target control, but just to be sure can you please share a descriptive screenshot (especially of the 2nd issue, I'm having trouble pinpointing the cause)?

Hi! sorry for such a late reply, I thought my comment had gone through but i guess not. heres a video of the issues i talked about. i’ll check out the new version of the app when i get home and see if these issues are in the new version or not.

Thanks for the detailed video!

The image file extension issue should now be resolved. It was an interesting issue (*.png does not work whereas *.PNG does...)

Although, I'm not sure about the image not showing up at all, I added a 50 ms delay for image to be loaded, suspecting it might be due to a failure to load in time. I hope it also is fine now.

Thanks for your input, I always appreciate it!

Oh, I think I solved the images-not-showing-up problem as well. Feel free to let me know if anything comes up!

Will do! Thanks

I find I still can't see the edit object tab or search bar. It wouldn't be so bad if it weren't for the fact ctrl + e doesn't seem to work for whatever reason most of the time.

This is a bug caused by custom Windows skins that aren't part of the default package.

Oh yeah, I feel like I saw that mentioned once. Hopefully it's something that can be fixed on nebulous' end.

You mean on /tg/? That was me.


This is quite nice. Easier to use than a tiddlywiki (open source wiki thing), with easier saving and interface.
A bit confusing to at first navigate, but I will be making a tutorial for it! I hope that's ok :>

Perfectly OK! I thought it was intuitive but apparently there is some confusion out there. Perhaps I cannot see the forest for the trees as the author... A tutorial would definetely help others too, I could share a link to it!

It's really confusing to move around and i don't really know what i am doing at all. Can there be a more easy to navigate UI? 


the last update is awesome, especially the nebulograph!

Would love a Linux port, maybe consider making it open source so someone else can make a port if you cant

Difficult suggestion: adding a music track or audio files for certain entries.

I have a suggestion for this; locking field visibility with a password. This would allow me to make an entry that says "John Doe is the bartender of The Pub" and a locked category that says "He's working for Bigbad and uses false bounties to send heroes to their deaths". This would allow GMs to distribute the file and not have players come across spoilers.

Sure, they could just export it, but that's a player problem.

This is an interesting idea and sounds easy enough to code. I will consider it, the only problem: the save file is essentially a text file (although a little hard to navigate) and it can be opened in notepad. I could encode the secret fields in some way perhaps... 

no json? 

"DMVisibility" : "visible",
 "GeneralVisibility" : "hidden" 


An absolutely wonderful tool for worldbuilders, and a must have for any writer.

It's a direct window to the large world inside your head, and what's more: one you can show other people!
You can add text, images and timelines to organize everything as you please. One of its best features is that you don't need an internet connection to use it or save it so it's very convenient. Also it's a WIP so it will get even better eventually.

Thanks for this, I really needed it.


Thank you for the kind review! I am glad it is helpful

Is the timeline a feature? If not, how do you do timelines?

As I can't run this yet:

The "Mindmap" hierarchical diagrams are nicely laid out. 

Can anyone say if you can have more "circular" links shown.

 e.g. a node has more than 1 link above it. 

e.g. show that  Romeo is a soldier and Romeo is a Montague and Romeo is engaged to Juliet and Juliet is a Capulet and Capulet clan is in a feud with Montague clan?

You may create the same name under different categories, however it is rather challenging to have one object under multiple categories with the current logic. I suppose "tags" could be implemented, but I need to think about how it would affect the system overall.

Hi, this looks good from this page. However, I can't run the file because VirusTotal reports that Cynet, Malwarebytes and MaxSecure flag v3.0.exe as malicious and Avast cannot confirm it is Ok.

Thanks for your interest!

Avast verifies it for me :) 

I honestly do not know what other malware tools recognize as malicious, the code is quite straightforward... I suppose the "exe" extension has a deserving notoriety.

Viewing most recent comments 1 to 40 of 46 · Next page · Last page