'In the beginning Bharat [the developer]
bought a digital camera and thought "wouldn't it be nice if I could put
these photos somewhere." But when Gallery 1.x came into being, the
developers had no idea what they were doing. They didn't know PHP very well,
didn't understand the importance of separating code from content,
didn't have a whole lot of database experience, you get the idea. So they
started by just writing something that worked, and then slowly building
upon it. The end result is Gallery 1.x which works quite nicely but
internally is a bit of a mess.'
http://codex.gallery2.org/History