I've saved up some money and am interested in doing something different for a bit. If I quit my job to work on some open source projects (probably mostly existing, but open to new projects too) what should they be?
I would like to sort of copy Weebly but make the core and all or most of the components totally open source and have a strong index/rating system for sharing and loading components etc. I would write it in ToffeeScript(https://github.com/jiangmiao/toffee-script) using Node.js.
I would also like to make something sort of like a web browser, except its based on a distributed hash table or something so that it is totally data-oriented rather than server-oriented, and instead of HTML and CSS its markdown (with embedded SVG) and optionally RDF (using N3) and optionally a sandboxed Go application that is compiled on the fly. Also the applications aren't restricted to a browser window but have a security system and access similar to that available on mobile.
Or a mesh of user-defined 3d worlds built on WebRTC and WebGL with portals and multidimensional overlays.
I think you should work on Factor: http://factorcode.org/ It's a new and very different programming language that takes about a month of study to learn. After that it will totally blow your mind showing you new and better ways to write software. So embrace Factor and spread the message! :)
I just saw a post on here about TextBlob - a python natural language processing library. It occurs to me that we need an open source alternative to Google's language processing (as seen on Android and in Google Now). We already have good speech recognition... If I had the chance I'd do that, maybe it'd interest you.
If you're going to do Blender stuff, my vote would be to focus on interoperability with other applications. In particular, Blender needs a working Alembic import/export function, IMO.
Play Framework. A very promising framework on the JVM which could supplant Rails/Django at some point with far better performance and robust enterprise features.
Gittip lets people give money to their favorite open source contributors.
https://github.com/gittip/www.gittip.com
CodeDoor is a way for programmers to leverage their open source contributions to freelance work. (Note: I'm the founder of CodeDoor)
https://github.com/CodeDoor/codedoor