Onyx IDE

DOWNLOAD NOW! (Cross-platform JAR)
DOWNLOAD NOW! (Windows Application)
DOWNLOAD NOW! (Mac Application)

Every UnrealScript programmer knows that when it comes to editors, the choices are slim. Even harder to come by is support for things like autocomplete, Intellisense, and the features that you’d expect out of a high-end IDE in any other programming language. That’s why I started Onyx. Built from Java, it can run on any OS with JVM installed. And what’s more, syntax highlighting and Intellisense are just around the corner.


  • Works on Windows AND Mac!
  • 16 beautiful themes!
  • Class tree viewer links to UnCodeX!
  • UnrealScript syntax highlighting
  • Support for multiple open files in separate tabs
  • In-editor compiling, options to run UDK Game
  • Tab/space conversion and cleanup
  • Toggle seeing whitespace (tabs/spaces)
  • Bracket auto-complete and folding
  • Intellisense (currently loaded with C-library, so it’s kind of useless)
  • Drag-and-drop to open files, open multiple files, open from the command line

(2-16-2013): Onyx IDE source code now on GitHub. Here’s the relevant blog post.
(4-11-2012): Mac application version now available!
(4-6-2012): Partial Help topics, numerous bug-fixes, Windows executable version
(3-4-2012): Added in-editor code compiling and UDKGame launcher (Windows only)!
(2-18-2012): Added full UnrealScript syntax highlighting!
(2-15-2012): Fully loaded class tree, double-click tree node to link to UnCodeX online!

Download: Onyx IDE.jar
Download for Windows: Onyx IDE.exe
Download for Mac: Onyx IDE.app


  • Class Tree Viewer — Source directory tree with ability to toggle to class tree
  • Intellisense — At least support for basic, most-used functions and keywords, although full object-oriented sensing is possible
  • Windows-only Options — Adding extra compile and run options via a separate menu, adding more intelligent file checks

Making the class tree and Intellisense libraries will be a real pain! If you want to help ease the burden, or if you want to help with coding, please email me at willyg302@gmail.com.

Robert Futrell (RSyntaxTextArea: syntax highlighting, code folding, autocompletion)
Michael Hagen (JTattoo: custom Java window themes)
JAlbum (portions of base code and RSyntaxTextArea integration)

Onyx IDE is a completely free product. Help to keep it that way by donating! Just click on the button above; any contribution is welcomed (powered by PayPal).

8 thoughts on “Onyx IDE

  1. 1. Onyx.jar contains duplicates of all jars from “lib” folder. Clean it.
    2. Have you ever think to make it Open Source?

    • 1. Strange…and yet it doesn’t run standalone. Any idea how I could go about doing that?

      2. Yes, but I want it to be in a more “finished” state before I make all the code public. For now if you would like to help develop you can email me and we will talk more.

      • Hi Willy,
        I did similar project using RSyntaxTextArea before , very nice project it’s support auto complement, auto intent and much more.

        and the standalone problem , try “Advanced Installer ” support .Jar Project’s
        event without JRE installed on the client Machine and also
        Cross-Platform Installer

        Very Nice Editor , i am using it as my default Script Editor ^_^

      • pastaman…i wonder if you’ll get this 😛 i cannot reply to your comment because of how my wordpress is set up…

        anyways, thanks for the link! I already figured out how to make standalone, exe, and app versions but an installer is definitely helpful. and i’m glad someone other than me is finding some use in this project 🙂

  2. Hello. Thank you for your excite tutorials on Youtube!
    I just started some UDK project and seeking for best IDE.
    I have a question about OnyxIDE. How I can select my project in it? Which folder in project I must select? (OnyxIDE said ‘Not a valid UDK directory’ for all folders in my project)

    • Hi, thanks for trying Onyx!

      The UDK Directory is the entire UDK folder, so for example mine is “C:\\UDK”. The reason for this is you may have multiple UDK versions (like “C:\\UDK\UDK-2011-03” and “C:\\UDK\UDK-2012-07”) at the same time. This allows Onyx to always be able to compile and run the right game, no matter what file you have open.

      Hope that helps!

  3. Pingback: Sublime Text 2 + UnrealScript | WillyG Productions

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