Nope, can't understand why IKEA offers some BILLY doors at full height only. Case in point, the OXBERG glass door. If you're in the market for half-height glass doors and do not plan on hacking the OXBERG, then this is for you.
BILLY bookcases with GRYTNÄS glass doors (IKEA Hackers)
IHeart Organizing: Built-In Bookcase - DIY Mirrored Doors going to make enclosed bases for the x bookshelves im doing for livingroom - can also do the same for the entertainment center I am building - may even do mirrors