VirtualBox is a general-purpose full virtualizer for x86 hardware. Targeted at server, desktop and embedded use, it is now the only professional-quality virtualization solution that is also Open Source Software. run bsd on a mac.
Gobby is a free collaborative editor based on libobby, a library which provides synced document buffers. It supports multiple documents in one session and a multi-user chat. It runs on Microsoft Windows, Mac OS X, Linux and other Unix-like platforms.