Today has been a big day for the virtualization market. VMWare's IPO is now under way, and we've seen good news for the company all over the place. After a very short length of time, their stock gained upwards of 76%, with the company now valued at around $20 Billion.

That's definitely looking good for VMWare, who have a near-monopoly on the existing small (albeit rapidly growing) market.

In similar news, XenSource looked to steal just a tad bit of VMWare's thunder, with a new release of their competing suite. XenEnterprise Version 4.0 has been released, bringing with it a lot of new support and features useful for server virtualization, such as 64-bit support. They have lagged behind VMWare in terms of raw support for a while, but are the most likely contender to be a serious competitor for them for a long while.

Things are definitely heating up in virtualization. It's going to be fun to watch.