Tachibana General Labs is one of main corporate entities in the anime series Serial Experiments Lain. It is the company that manufactures the Navis and Copland OS. The former employers of Masami Eri, and don't approve of him and his seventh IP protocol.
Tachibana has an interesting relationship with Lain, at one point they even try to trick her into helping them find out who The Knights are. She eventually leads them to their "hideouts", interesting things begin.
Tachibana is also part of the reoccuring themes in Lain with Apple, The McIntosh is an apple variety, hence the "Apple Macintosh". It turns out that Tachibana is a citrus variety, specifically Citrus tachibana from Japan, better known in the US as Mandarin Orange.