What is WMA file?

Windows Media Audio
File extension: .wma
MIME type: audio/x-ms-wma
Uniform Type Identifier: com.microsoft.windows-​media-wma
Developed by: Microsoft
Type of format: audio file format

What is OGG file?

File extension: .ogg
MIME type: application/ogg
Magic: OggS
Developed by: Xiph.Org Foundation
Type of format: Container format
Container for: Vorbis, Theora, Speex, FLAC

Ogg is an open standard for a free container format for digital multimedia, unrestricted by software patents and designed for efficient streaming and manipulation. Ogg is maintained by the  Xiph.Org Foundation.

Convert WMA to OGG with Mini-stream Ripper

For .ogg is not a patented format, more and more free and commercial media players begin to support this format, and even some portable media players can play .ogg media files. .mp3 is a good encoding format, but since it was patented, it can bring up some patent-based lawsuits. Besides, more and more game engines begin to support .ogg, and games like Doom 3, Unreal Tournament 2004 and Serious Sam have already employed .ogg.

Sponsored by a lot of media player manufacturers and music publishers, more and more music manics prefer to convert all the other audio files into .ogg files and wma2ogg conversion is commonly used. Mini-stream Ripper renders this conversion with breeze, and the function of batch conversion can convert all the .wma files in a whole directory into .ogg at one time.