The following article by Matt Assay comments on some notable IT vendors (closed & open source) and speculates on who has enough cash to weather the recession.
I'd like to comment on the obvious advantages of open source companies is that they can share risks, development costs, and other costs with their ecosystem/community. Similarly, the try-before-you-buy nature of open source may also take the edge of sales costs. Thus, it stands to reason that provided they have a equivilent sized revenue base, they should fare a little better than an equivilent closed source company.
Enjoy: