The Lithuanian TeX Users Group (LT-TUG) is a volunteer society of TeX users (in academia and science related field) that develops and promotes the use of TeX and related software in Lithuania. More information about this group and how to became a member of LT-TUG can be found at www.ltex.lt (in Lithuanian language).
TeX is a typesetting system (https://en.wikipedia.org/wiki/TeX) which was designed and written by Donald Knuth and first released in 1978 and has been noted as one of the most sophisticated digital typographical systems. It is also used for many other typesetting tasks, especially in the form of LaTeX, ConTeXt, and other macro packages.
Lithuanian TeX Users Group is a member of world wide TeX User Group, which is a membership-based not-for-profit organization, founded in 1980, for anyone who uses the LaTeX typesetting system and/or is interested in typography and font design (https://tug.org/).