The following is a list of creators/maintainers of some of the most important API/packages/applications that a lot of people use with MySQL.
We can't list every possible package here because the list would then be way to hard to maintain. For other packages, please refer to the software portal at http://solutions.mysql.com/software/.
For the DBD (Perl) interface.
For the Perl interface for MySQL Server.
For maintaining the Perl DBD::mysql module.
For porting PHP for MySQL Server.
MySQL 4.1 testing and bug hunting. New PHP 5.0 mysqli extension (API) for use with MySQL 4.1 and up.
For porting iODBC (Unix ODBC).
The author of LinuxThreads (used by the MySQL Server on Linux).