Hi Golem,
VMWare Workstation has two different flavours :
- Workstation "Pro"
- Workstation "Player".
Both can do the same, and both are BASICALLY paid software...
But as "Workstation Pro" has more advanced features (that you may never need) it costs more than "Workstation Player".
And VMWare explicitly says that the use of VMWare Workstation Player is FREE if you do not use it for commercial needs.
Of course, this is then between you and your conscience :-)
Upon install of Workstation Player you're asked for a serial number, but can decide to leave that field blank by stating that you will use it for a non commercial use.
I think all Workstation versions are equal performance wise. They just differ features wise.
As I haven't used Workstation before a few weeks, I can't tell if you will get any benefits if you upgrade an older version.
Regards.
FRED