All programs on these sites have GPL_License, latest edition. Some of these programs have several versions. The content from the books is quoted in the first placed it is used.
In making these programs, I used the Mono_C#_Compiler (mcs) and KWrite text editor. For C/C++ I used gcc/g++. For a graphical interface, try Visual_Studio (for C/C++ try CodeBlocks). See also the Visual_Studio_tutorial_for_C#.
See my Google_Developer_Profile.