The TRAC system for Text Reckoning And Compiling. One of the first HomoiconicLanguages, created by CalvinMooers and PeterDeutsch.
While the language was well-known and influential in the late 1960s and early 1970s, Mooers vigorous defense of his copyright and trademark on the language, including against those trying to cleanly reimplement the language (that is to say, without using any of the original interpreter source code) drove away many who were interested in it, and the language never saw widespread use as a result. At least one other language of the time, SamSeventySix?, was clearly influenced by TRAC (but also by ForthLanguage and LispLanguage), to the extent that Mooers unsuccessfully sued the developers of SAM76 over it; the similarity was such that some observers claimed that the name stood for 'Same As Mooers' (according SAM76 designer to ClaudeKagan?, it was actually based on the initials of ChristopherStrachey and DougMcIlroy, developers of the macro languages GPM and M6 (respectively), which he says were the most direct influences on SAM76).
See http://tracfoundation.org/trac64/handling.htm and http://www.tracfoundation.org/ in general.
"TRAC, A Text-Handling Language" by C. N. Mooers and L. P. Deutsch (1965) Paper presented at the 20th National Conference of the Association of Computing Machinery, Cleveland, Ohio, August 1965.