There are a whole lot of variations on the “source code available” idea.
variations on source code theme
+------------------------------------+
| tag |
+------------------------------------+
| I6 source available |
| I7 source available |
| BASIC source available |
| Source Code | ***
| source available | ***
| TADS2 source available |
| AGT source available |
| PunyInform source available |
| C source available |
| TADS3 source available |
| Twine source code available | ---
| Hugo source available |
| source code available | ***
| ZIL source available |
| T/SAL source available |
| Alan source available |
| JavaScript source available |
| INSTEAD source code available |
| Dendry source available |
| Adventuron source available |
| GAGS source available |
| Pascal source available |
| Quest source available |
| I5 source available |
| Java source available |
| adventuron source code available | ---
| Twine source available |
| Assembly source available |
| source | ***
| Vorple source available |
| Basic Source Code | ---
| Squiffy source available |
| ADRIFT source available |
| AdvSys source available |
| Visual SINTAC source available |
| JACL source available |
| FORTRAN source available |
| TIGSource | ???
| game source NOT actually available | !!!
| PHP source available |
| Gruescript source available |
| Typescript source available |
| Undum source available |
| I7 Source Code | ---
| Inform source available |
| C++ source available |
| ChoiceScript source available |
| Clojure source available |
| Emacs Lisp source available |
| Magx source available |
| A-code source available |
| Forth source available |
| MAPPER source available |
+------------------------------------+
They’re sorted in order of descending usage. The tags I marked with asterisks seem to be variations on the general category.
I would think that some people would find value in the language/system-specific versions, but I see some candidates for consolidation. By far the most common phrase in use for the concept seems to be “source available”, so I would recommend that as the generic tag.