Bitcoin is an encrypted software that runs through p2p (meaning it is not anywhere, but everywhere).
The design, when set off, has hard coded rules that can not be changed eg. 21m cap.
The software stated that 50 coins would be made every 10mins for 4 years, then every 4 years after that it is halved.
Miners income is planned to stay static based on more bitcoin users = more transaction fees. (overcrowding could be an issue)
ALL new coins are issued to miners (at present time that is 25 coins every 10 minutes)
If I've missed something, just let me know
ALT coins are just copies of the current software (an improvement would be nice), and therefore unlikely to become any more stable than what bitcoin is now.
K.