utilities & tool(s)

taken from: www.reddit.com/r/gamedev/comments/18e38t/pocketknives_for_game_developers

I'm compiling a list of "pocketknives" for game developers, in that they're tools (not just resources) that:

do One Thing Well
are portable, as in, permissive license, exports usable data, and fits in any workflow.
are free web apps, so there's no cost, no download time, and no cross-platform issues.

After reading the comments, I've loosened the 'web app' criteria, (marked with an asterisk) as long as they're still free & cross-platform. And as great as downloadable tools like Audacity & Blender are, I'd like to keep the spotlight on the lesser-known gems.

Here's what we've got so far:

Art

Spritesheet Cutter: http://spritecutie.com/ (created by /u/Rezoner)
Turn photos to 8bit: http://superpixeltime.com/ (created by /u/FamousAspect)
Simple 3D Modeller: http://www.3dtin.com/ (Thanks /u/TannerNetwork!)
SVG Vector Art: http://svg-edit.googlecode.com/svn/branches/2.6/editor/svg-editor.html
Photoshop-like Webapp: http://pixlr.com/editor/ (Thanks /u/2Fort!)
Pixel Art: http://makepixelart.com/free/
Pixel Art Analyzer: http://hivemind.in/pj/specs/ (Thanks /u/MoarThenFeeling!)
Pixel Animation*: http://www.pickleeditor.com/ (Thanks /u/LoveDuckie!) *Adobe Air app
Pixel Tileset*: http://pyxeledit.com/ (created by /u/Danik112, suggested by/u/InlineVoid) *Adobe Air app

Audio

Make Music #1: http://soundation.com/studio (Feels like GarageBand. Thanks/u/optimality!)
Make Music #2: http://www.audiotool.com/app (If you like sliders and knobs)
Make Music #3: http://www.beepbox.co/ (Super-simple chiptune loop creator. Thanks/u/Spajder!)
Sound FX #1: http://www.superflashbros.net/as3sfxr/
Sound FX #2: http://www.bfxr.net/ (Newer revision of sfxr. Thanks /u/ethicszen!)
Sound FX #3: http://www.leshylabs.com/apps/sfMaker/ (An HTML5 version of sfxr by/u/LeshyLabs)
Convert OGG/MP3/WAV: http://media.io (Thanks /u/Bionsuba!)
Convert WAV to MP3: http://audioformat.com/wav-to-mp3 (Thanks /u/RyeBread761!)
Procedural Tunes*: https://github.com/wibblymat/ld24/blob/master/autotracker.py(Thanks /u/Cosmologicon!) *Python script
~~Wolfram Tones: http://tones.wolfram.com/generate/ (MATHEMUSICAL. Thanks/u/BluShine!)~~ Turns out Wolfram has a non-permissive license for the tunes it procedurally generates, so you can't use them in your games. Uncool. Thanks to/u/ethicszen for the correction!

Data

Placeholder Kittens: http://placekitten.com/ (To test loading external images / image manipulation.)
data:text/html, <html contenteditable> (Paste into your address bar for an instant in-browser notepad)
JSON Prettifier: http://jsonsh.com/
JSON Lint: http://jsonlint.com/ (Thanks /u/Skjalg!)

Design

Tile Maps: http://elias-schuett.de/git/Online-Tile-Map-Editor
UI Wireframing: https://moqups.com
Flowcharting game flow: https://www.lucidchart.com (Thanks /u/MX-Chronos!)
HTML5 Level Editor: http://www.craftyy.com (Full disclosure: /u/CosmicJC & I made this.)
Game Mechanics: http://www.jorisdormans.nl/machinations/ (Thanks /u/Quantanamo!)
Grid Map Editor*: http://www.arraypainter.com (Thanks /u/oldsecondhand!) *Standalone Java app
Tiled Map Editor*: http://www.mapeditor.org (Thanks /u/KillaW0lf04!) *not web app

Production

Organization: http://corkboard.me/ (Automatically creates your organization "corkboard", no login needed!)
Collaboration: https://trello.com/ (Thanks /u/MatticusRex & /u/Reaner!)
Screenrecording*: http://www.screenr.com/ (Screencast without downloading anything) *Warning: It uses the Java web applet, which hasn't had a great track record with security issues.

Programming

Regex: http://regexpal.com/ (Thanks /u/Noctune!)
Collaborative Coding: http://collabedit.com/ (Like Google Docs for programming. Thanks/u/BluShine!)
Gist: https://gist.github.com/ (Good for sharing snippets of code)
Pastie: http://pastie.org/ (Pastebin with plugins available for Sublime & TextMate. Thanks /u/agmcleod!)
Making JS+CSS+HTML #1: http://jsfiddle.net/ (Thanks /u/MurderOfCrows!)
Making JS+CSS+HTML #2: http://codepen.io/ (Thanks /u/Azeirah!)
Making JS+CSS+HTML #3: http://cssdeck.com/ (Thanks /u/Rezoner!)

Resources (Not really "tools", but they're still quick one-stop websites.)

Open Game Art: http://opengameart.org/ (of course)
Pocketknives for Javascript: http://microjs.com/
Game-specific UI Icons: http://game-icons.net/ (Thanks /u/AutumnGecko!)
General UI Icons: http://thenounproject.com/
Fonts #1: http://www.google.com/webfonts (Free, open-source, and you can simply embed them)
Fonts #2: http://www.dafont.com/ (Licenses vary, mostly free for personal use)
3D Textures: http://www.cgtextures.com/ (Thanks /u/Brother_Clovis!)
Sound effects: http://www.freesound.org/ (Thanks /u/Connerses!)

Surely I've missed a few. If you know of a good "gamedev pocketknife", leave it in the comments, and I'll update the list above! (and credit you for the suggestion) Or, if you want to request a type of tool, I'll add it to the list below. Don't worry about being too specific!

Does anyone know of free web apps for:

~~Vector graphics~~ (http://svg-edit.googlecode.com/svn/branches/2.6/editor/svg-editor.html)
~~3D Tools~~ (http://www.3dtin.com/ found by /u/TannerNetwork)
Tween Animations
Non tile-map level editors
Character creation
Dialogue branching
Story
Texture Generator
A tool to make tools because why not

SAY WHAT? #1 Post of All-time on r/gamedev?

Thank you all for the overwhelming response! Just today, this list has grown from ten entries to dozens of tools. Making this list has surely helped me, and hopefully it's helped some of you too! There's also a lot of great discussion in the comments below, ranging from web apps to Wolfram.

Stay awesome, r/gamedev.