Eric S Raymond, affectionately called ESR, has called on Sun Microsystems to let Java go and make it open source just like they did for NFS which went on to become very popular. This article has created a lot of controversy in the open source community.
The truth is that Sun Microsystems has done a lot for the open source community and their contributions are invaluable - from OpenOffice.org to XEmacs. Of course, Java is currently not open source but there is nothing preventing an open source implementation of it. I think Sun Microsystems has business concerns in mind which is keeping them from making Java open source, but this does not undermine the fact that they have contributed a lot to open source and is indeed a respected member of the open source community.