Probably, Scilab will soon be GPL/LGPL, although this is extra-official. Currently it is open-source but the commercial use of its modifications must be approved by the authors. This is the only difference of its license to the GPL. However, the original authors showed commitment to approve the use of all its sourcecode modifications. The license is not GPL due to an historical reason only, but in practice it can be considered GPL, and it certainly will soon be officially GPL (or LGPL).
An open, cross-platform journaling program.
A scientific plotting package.