IDC's "Worldwide Identity and Access Management 2007-2011 Forecast and 2006 Vendor Shares" has Quest Software listed as #15 in their table on revenue by vendor (report #207609) - just barely ahead of Microsoft.
IDC has PassGo listed as #24. The PassGo acquisition set to close on January 1st, but if you add up Quest's and PassGo's revenue we jump from #15 to #10. That puts Quest Software solidly ahead of Microsoft and Sun.
My personal stretch goal is to get in the top 5 (software vendors) within the next 5 years...
Quest Software, identity management, PassGo