OMG, I am surprised that the questioner took for granted, according to his comment from Jul 31 2011, the completely misleading and wrong answer (every phrase of which is wrong), having ignored link in another answer from Jul 30, 2011 with quite exhaustive considerations:
Customizing standard list forms, or publishing forms to a form library
Enterprise Sharepoint is required only for running Infopath forms through IPFS - Sharepoint Server Infopath Form Services, i.e. opening them in browser. It is not required for opening IP forms in Infopath Filler (on client machines). Even if one has enterprize Sharepoint Server, using only Filler/client forms is in most cases more preferable since they have richer UI features vs. very restricted and limited web- or browser forms!
It is possible to publish IP forms into Sharepoint libraries (in Infopath Designer), customize Infopath forms and open them from sharepoint libraries locally, on client machines, in Infoapth Filler though it require installing Infopath on all client machines. Though it rarely a restriction as Sharepoint is mostly used in intranets and enterprise environments having Microsoft Office suite installed anyway.
Besides it is possible to use Infopath forms:
- both without Sharepoint
- or publishing them to client machines using only Sharepoint Foundation
Also, to note, that one can use enterprise Sharepoint Server without owning or having a SP server through cloud Sharepoint Online as part of Microsoft Office 365 subscription plans.