Conlang stands for constructed language. Many people created conlangs for hobby or as linguistic experiments.
I was inspired by the conlangs in Inheritance Cycle and The Lord of the Rings, as well as others like Esperanto, Dothraki, Toki Pona, et al and conlang from time to time as a hobby. None of my conlangs reached its maturity, though, mainly due to loss of copies and lack of time.
Some of my conlangs: