For anonymous access, simply issue the command 'svn co http://svn.hyperic.org/projects/sigar'
For developer access, send email to sourceforge user "hyperic".
The latest release of SIGAR 1.4 is out! This fixes a couple of bugs, one of which affected User Mode Linux users wishing to get CPU info.
Download from http://sourceforge.net/project/showfiles.php?group_id=172552&package_id=197466
See docs at http://support.hyperic.com/confluence/display/SIGAR/Home
SIGAR discussion forum: http://forums.hyperic.com/jiveforums/forum.jspa?forumID=2.