Aacplusenc
aacplusenc is a multiplatform HE-AAC+ encoder.
It was written by Matteo Croce that tooks the 3gpp reference code and wrote his own routine to read wav files, write RAW ADTS output as well as faster buffered I/O and custom FFT routines
The encoder now supports mono and stereo encodings, it's not as good as the Nero encoder but is way faster.
Also, it's the only HE-AAC+ on certain combination of Operating System/architecture like MacOSX, Linux/PPC etc.