These are source files for Zelda Classic, covering historical releases, as follows:

1.00
1.50
2.10.0
2.10.1
2.10.2
2.10.3 (may not have been released)
2.50.0RC1 (b1401)
2.50.0RC2
2.50.0RC3
2.50.0RC4
2.50.0RC5
2.50.0 (Final)
2.50.01RC1 (build 1608)
2.50.1RC1 (build 1628, may be the actual RC1)
2.50.1RC2
2.50.1RC3
2.50.1 (Final)
2.50.2 (Final)
2.50.3RC1 (Abandoned)

Sources for versions 1.6x through 1.93 are not available at this time. 
These are provided as-is with no support for compiling. 
Required headers, libs, and deps, may be missing from some packages (1.00, 1.50).