[fpc-pascal] Newbie, Delphi porting: Which are standard Units?

[Alexander v. Below]

Hello,

sorry for asking such a total newbie question, but I have some  
(apparently) Delphi code and I my goal is to examine if it is feasible  
to port this to Mac OS X.

Now, it lists a lot of units, and google is not very helpful. So my  
question is: Are these standard Delphi units? Third party? Most  
importantly: Are they somehow available on the Mac?

What is a good place to search for these?

uses
  Classes, Sysutils,
  U_Global, L_Lockdata, U_Strings, U_RegExpr, L_Wintol, U_Images,  
U_Stream,
  U_Tiff, U_Tiff_Tags, U_Tiff_Global, U_Pixels, L_Mathe, LeanOcr,  
U_Wininfo;

Thanks

Alex