txtSQL (pronounced "text-sequel") is a class containing a variety of functions designed to mimic a database system, using only regular text files. Running on the PHP language, it is object-oriented and can be looked at as sort of a framework in creating larger scripts (such as guestbooks, polls, forums etc.) There are two levels of access; a low-level implementation that works on just function calls and the other relies on the support of SQL (a parser/lexer is currently being developed). As far as I know, txtSQL is VERY efficient in how it handles its data and the way in which it is handled has also almost never caused any major concerns (data loss is rare). txtSQL does not require any outside plugins to operate, it's in the ballpark of "plug and play" (with a few exceptions of course). But most importantly, txtSQL is an opensource project (listed under Sourceforge), licensed under the GNU, which means that it's totally free of charge and will remain as such forever.