Check out www.dontronics.com or www.mcselec.com as there was a 1kb code limited free basic compiler BasCom51 available during the last year. I brought the Bascom51 full version as it's quite cheap and you get good support and upgrades from the programmer. It has built-in routines for lots of hardware eg. LCD, serial, I2C, RC5 infra-red... The list goes on and on.

I would suggest you buy the full version to get the most out of the software.