Just read­ing in a StudiVZ-Group about free­ware for bio­chem­istry brings me to the idea to post this:

Bio­bar Add-On für Mozilla Fire­fox:
Search in Pubmed, NCBI-Databases, EBI-Databases right from your Browser. No need to surf to the webfron­tend of the service.

Lab­plot für Linux (KDE):
Like Ori­gin. You can use Lab­plot for regres­sion analy­sis, cre­at­ing graphs from data …