The kernel is getting more and more stable and much of the Win32 GDI has been completed, but there is still a lot to do.
Work has begun porting WINE from the Linux platform though it can't be completed without a fully functional GDI. If you can offer any help with any part of this project then please visit reactos.com and subscribe to the mailing list to find out what's going on at present.
An open, cross-platform journaling program.
A scientific plotting package.