I do not know where the initialisms ESX and GSX stand for. They may simply
be meaningless marketing terms or related to project names that were not meant
for public consumption. I'm simply curious. Can anyone find a
reasonably definitive explanation of what these terms expand to?

Hi plookyplok-ga,

The initialisms "ESX" and "GSX" in the VMware product names "ESX
Server" and "GSX Server" don't stand for anything.  As you guessed,
they are "meaningless marketing terms."

My source for this answer is Kay in Sales Support at VMware, Inc.
corporate headquarters in Palo Alto, California, USA.  I talked to her
on the phone and she kindly investigated and provided the definitive
answer.

Best regards,

--efn

I appreciate when answerers use tools other than the internet to get
information. I don't know why I didn't think to call vmware
directly...

plookyplok-ga:

I think the only folks who can provide you with a definitive answer
are at VMware, but here's one way to look at it (as suggested by an
answer in the ESX FAQ at
http://www.vmware.com/products/server/esx_faqs.html ):

"How Is ESX Server Different from GSX Server?
ESX Server is designed for up to 16 processor departmental and
enterprise servers, and runs its virtualization layer natively on
hardware. VMware GSX Server is designed for up to four processor
workgroup and departmental servers. It runs as an application on top
of a host operating system. The major differences are..."

From this, I would infer that the letters 'E' and 'G' refer to
'Enterprise' and 'Group', while the letter 'S' stands for 'Server'. I
have no idea what the 'X' stands for. As well, while the 'E' and 'G'
definitions may have been relevant in their original version 1
releases, the distinction is no longer as relevant, since the current
release of GSX is targeted at multiple platform environments, while
ESX is targeted at high-demand enterprise environments.

Regards,

aht-ga
Google Answers Researcher