MESearch, expanded as Mathematical Expression Searcher, is a program written by Xuru (full name Jon Zurutuza Salasmendi).
Formerly it lived at xuru.org, but now the website is dead.
To give this nice, despite its uselessness, program some more chances against bitrot, it is now here.
Program, needs Java, whitepaper, 162 pages, Original webpage (don't click on links, just a single page is kept here).