I would like to have bitcoin and store them as safely as possible. I want bitcoin data to be stored on my disk -- I don't want to some online service to manage my wallet. I also would like to have ability to easily backup wallet data so if my disk fails I can then recreate my wallet from backup.
Nice thing is to have ability to transfer wallet from one program to another so if some program ceased to be developed I can import my private/public keys to another program.
Can you recommend any application like that?