I could but im using a licenced/registered version of it.
What difference does that make? The point is:
Free Pascal (aka FPK Pascal) is a 32 and 64 bit professional Pascal compiler. It is available for different processors: Intel x86, Amd64/x86_64, PowerPC, PowerPC64, Sparc, ARM. The following operating systems are supported: Linux, FreeBSD, Haiku, Mac OS X/Darwin, DOS, Win32, Win64, WinCE, OS/2, Netware (libc and classic) and MorphOS.
It would allow you to extend your skills.
edit: I have no association with freepascal.org. I have used it a few times. I used Delphi from V1. Last version I had was V7 Architect - The last of the native compilers, before .Net ruined it.