YMPEG is Windows AVI codec (VFW). After installation, it becomes part of Windows so that it can be used by any application which uses Windows Compression Manager (like VirtualDub, Adobe Premiere, AE, Vegas etc.). It can also be use for real-time MPEG encoding.
YMPEG is a first MPEG Codec which can integrate itself with Windows and offers seamless encoding from your favorite application.
During evaluation period, there is no difference in YMPEG evaluation and registered version, except that YMPEG evaluation version displays splash screen while registered version does not.