  Learning computer programming has been always challenging. Since the sixties
of the last century, many researchers developed Visual Programming Languages
(VPLs) to help in this regard. In this thesis, ten VPLs were specifically
selected, studied, experimented with, and evaluated. A total of fifteen metrics
were used to evaluate the tools. Comparisons, classification, and gap analysis
were then presented. A list of requirements for a general-purpose VPL and a
guide to help the novice programmer choose the right tool were generated and
finally the PWCT (Programming Without Coding Technology, a novel
general-purpose visual programming language) is developed and presented. PWCT
has been launched as a Sourceforge project, which currently has more than
230,000 downloads for the language and more than 19,500,000 downloads for
samples, tutorials and movies. Many business applications and projects are
developed using PWCT, Also we developed the Supernova programming language and
the Ring programming language using PWCT to prove that it can be used for
advanced and large projects. Feedback from developers and results from the
studies indicate that PWCT is a very appealing, competitive, and powerful
language.
