how to download only orbeon designer

hai ...
This is srividhya...working in N.I.C as researcher...Now am working on Orbeon server... i have 2 queries
1. Is it possible to download only orbeon designer ....If yes means what is the procedure to download..
2. How to design the form in offline mode..(send me some sample code (like hello world program....))


with thanks and regards,
Srividhya.N