Atmel has some derivates with ISP.
However be carefully, some old parts are signed as ISP but is not done in the serial uart, it is done trough the spi port wich is a bit more dificult. Atmel gives you the circuits, aplization... to do this.

With the 'new' devices with 'uart ISP' you must use the aplication flip. Take a look in Atmel's web site.


You can done IAP too is easier than it seems!!


Regards.