Hope that it’s not already posted elsewhere (the search function is not working properly to me ATM)…
[li] First in the world FREE 2-Pass MPEG-4 AAC Encoder
[/li]> [li] Compression Ratios ranging from ultra high (58 CDs fit on one!) to High-End Audio (2.5:1), for absolutely perfect audiophile encodings
[/li]> [li] Crystal Clear, Award Winning Sound Quality at every compression ratio and bit rate!
[/li]> [li] Support for Embedded Album Art (Covers, Booklets, Lyrics!)
[/li]> [li] Store Entire Audio Album in a Single .mp4 File with all the Features of an Audio CD embedded inside, but at a fraction of the space!
[/li]> [li] Reference Quality MPEG-4 Audio Codec
[/li]> [li] Fully Compatible with the Latest Version of the State-of-the-art MPEG-4 Audio Standard (LC-AAC, HE-AAC and HE-AAC v2)
There is also a dedicated thread at Hydrogenaudio.