I wish to create shareware software that contains a registration algorithm. I am looking for a programming language, that cannot be easily decompiled into readable code. F
As Dominic said, if you can run it, it can be decompiled.
That said, I believe there are tools that obfuscate the compiled code and make it more difficult for someone to disassemble and reverse or take apart a registration process.
For example, I believe that major companies like Adobe and Microsoft use products like this, in order to make it much more difficult for folks to disassemble and crack their programs.
It's like security or cryptography or even the locks on your car/house - someone with enough time and resources can probably break through anything.
You just need to tilt the curve enough to make it sufficiently unattractive for anyone to really try, so that they'd be more likely to move onto easier targets.