License for Cross-platform Management Agents

[John]

Dear All,

Good day, I have recently deployed SCOM 2007 R2 at a client, they have
around 10Sun Solaris/Unix machines that they want to monitor from SCOM, I
have no idea about the license to get purchased for cross-platform management
agent because...I tried to install an agent on one Unix machine and it worked
successfully, i even saw the management packs already available in the SCOM
installation files, i imported the Unix/Solaris MP and the Unix machine
started working absolutely fine...

My question is, are there any license to be purchased for cross-platform
management agents ??

if no license requires then how is microsoft dealing with it..

Regards,

NS