The beginning of TeX can be dated back to the late 1970. Google Scholar finds for the author “Donald E. Knuth” from that area some papers, which are introducing TeX and metafont. The interesting aspect about the first papers of 1979 and later improvement is the very low speed the development itself. That means, the first version of TeX was presented in 1979. It takes until 1984 until Bibtex was ready, and in 1989 some type3 fonts were released. That means, a minor improvement took not weeks but years. And this slow development speed is an ongoing process. For example, it takes many years until the first version of Lyx was programmed. Literally, the TeX community is working since mid 1970 on his system and every 5 years or so, they have invented something new.
The first question which has to be answered is, does TeX makes sense? I think the answer is yes. The productivity is higher then with MS-Word and it has a high output quality. The next question is, how can we improve the current software. I would guess, future improvement have to build on top of Lyx. Lyx is the most important frontend right now, it uses an underlying bibtex and latex backend for generating the output. I would guess the most room for improvement is the sourcecode itself. Rewriting Lyx and LaTeX with modern C++ would be a nice task for future students.
The year which can be called the birthday of TeX was 1984. That was the year, in which the TeXbook was published (written by Donald E. Knuth) and in the same year, the LaTeX manual and the Bibtex draft was presented. The PDF format was unknown in that area, also Type1 fonts and the Lyx GUI. These developments came later. The basic idea behind TeX was to replace mechanical typesetting machines. The idea was to generate a printable document with a computer. TeX can be seen as direct competitor to Phototypesetting.
A long journey
According to the timeline it is a fact, that between each iteration of TeX many years were in between them. TeX was programmed in 1979, LaTeX in 1986, pdflatex in the early 1990s, Lyx in the late 1990s, Google Scholar in 2005 and so on. Each step adds an important functionality to the work done before, but the overall workflow took around 30 years. It is very likely, then in future improvements will come also in a period of 10 years or more. Why?
One possible explanation is, that the computersoftware TeX is used by people, and if new sort of users are become aware of it, they are programming an extension. The long years between each period has nothing to do with the software itself, but it’s adoption from a certain usergroup. Lyx is perhaps a good example. The Lyx community is different from the original Tex and LaTeX community. They are not familiar with the commandline or Emacs, but with MS-Word. So they have programmed their own TeX which looks like Word, but is more powerful.
Perhaps the future Facebook generation is not familiar with desktop applications, and they have a need for a Lyx version which runs in a browser window. I don’t know, because it is unclear what the future will bring.