Hello Gilberto,
[Topic moved here.]
This forum topic covers the status of support for Hauptwerk on OS X 10.10 ('Yosemite'):
http://forum.hauptwerk.com/viewtopic.php?f=10&t=13544
To summarise it, the current version of Hauptwerk (v4.1.1) should work fine on it, and we do support it.
Hauptwerk is always designed to be backwardly-compatible with sample sets that had been created for earlier Hauptwerk versions, and all sample sets should work properly in the current version of Hauptwerk, on any computer platform that we support for Hauptwerk.