is there any equivalent apps like Samurize, AveDesk, Kapsules, Konfabulator for Linux ?

Are you thinking of something like gdesklets? (it is for Gnome, but there is karamba for KDE)

Screenshots: http://www.lynucs.org/?gdesklets

The most common stuff is:
Superkaramba (only works on KDE)
Gdesklets (part of the gnome project, but should work on any WM. Lot's of required dependencies though, if you don't have gnome installed).
Adesklets (a lot like gdesklets, but doesn't require any gnome package as it's based on imlib2. There aren't that many gadgets available for it yet).

There're also docks like engage, ksmoothdock, kxdock, kooldock...