This category holds links on programming languages for which at least one body of writings, specification, or implementation exists, that meets the definition of open source software found at
Opensource.org. All links in this category point to languages that are already listed in the directory. On this page, languages are arranged in two groups and levels: 1) Top group: Languages where all versions are open source, none are closed. Such software usually began as open source, and stayed so, or was closed and then changed to open. 2) Bottom group: Languages where some versions are open source, some are closed. Such software usually began as closed source, and then one or more version changed to open, or one or more open source version was begun.