Lazarus is a Delphi compatible cross-platform IDE for Free Pascal. It includes LCL which is more or less compatible with Delphi’s VCL. Free Pascal is a GPL’ed compiler that runs on Linux, Windows, macOS, FreeBSD and others. Free Pascal is designed to be able to understand and compile Delphi syntax, which is OOP. Lazarus is the part of the missing puzzle that will allow you to develop Delphi like programs in all of the above platforms. Unlike Java which strives to be a write once run anywhere, Lazarus and Free Pascal strives for write once compile anywhere. Since the exact same compiler is available on all of the above platforms it means you don’t need to do any recoding to produce identical products for different platforms.