What kind of applications (software technologies) we can test efficiently using mercury QTP (quick test professional) ?

QTP stands for quick test professional which is a mercury’s product for automation testing (functional & regression testing) of below technologies.

Windows applications,
People soft
Java
SAP
ERP
Oracle
Siebel
VB
Dot net
ASP
Java script
And some Others…

Note: you need add-ins for using QTP on different technologies.
For example to work on ERP(SAP, people soft etc..) applications you need SAP add-ins, people soft add-ins etc…