Using Java, Jython (Python) to manage your vCenter/ESX/VI
If you use Java or Jython, then the VMware sponsored open source Java API is available for you. It's much easy to use and the LOC is much smaller.
I just released 2.0 which includes a new high performance web service engine -- 15 times faster in loading, 4+ faster in serialization/de-serialization than AXIS. The project is under BSD license, so you are free to redistribute your application without asking your users to download AXIS, which could be a pain point in marketing your products.
Jython support comes as free, check out the presentation: