VFP / FoxPro
Review VFP functions and commands and how they relate to harbour: VFP 9 Help File

If you are a Harbour developer you may wonder why this page exists.
There are so many VFP / Foxpro developers that could convert to Harbour, and so many of them have a lot of experience developing Desktop and Web apps. By welcoming them to Harbour, we can increase the size of our community.

If you are a VFP developer you may often wonder how we can port our program to other languages, or how can we develop web and mobile apps. We often think about the Microsoft Stack, C# / .Net with the MS SQL data solution, or PHP with the MySQL backend, or even Python with its huge options for packages and backend support. Other commercial solutions like Lianja and Xbase++ are also viable solutions for us. But if you want to develop with a language that is very similar to VFP and is open source, Harbour is the solution. With Harbour we have access to its source code, we don’t have to be worried about a single vendor controlling its future, and it is 100% free. Harbour was in development since before 1999, as a Clipper clone. Now it is incredibly stable and it can allow you to create apps that can run, not only on Windows, but also on Unix, Mac and Android. Even create 64 bit apps! Break the 2Gb files size limit, even for DBFs (256 TB). This will also allow you to create multi-threaded apps if you want. Harbour is a compiler which generates pure C code, from xBase like programs, but unlike other compilers, you can still use macros (evals) and do dynamic linking

The following article is a good place to start: Introduction to Harbour, an Open Source Alternative to VFP

The presentation can be viewed on YouTube