The Alay culture phenomena spans a wide array of styles in music, dress, and messaging.
One theory that is widely accepted is that "Alay" comes from the term "Anak Layangan" (Indonesian: Kiteflyer), a pejorative describing someone having certain attributes from spending most of their time outside and getting sunburnt (e.g. reddened hair and skin).
Alay text may have originated from the method of making strong passwords for internet accounts, which requires combinations of small and capital letters, numbers, as well as special characters.
Soon this becomes a habit in writing text in general, and improved with mixing English and Indonesian in one sentence.
According to The Jakarta Post, a high school student from East Java initiated the trend and became famous after her writings were discussed in forums and blogs not because they were great, but they were in "code".