You are searching a jpeg2000 plugin for your linux browser, you are in the right place here !
The plugin is using Netscape Plugin API and Jasper jpeg2000 lib.
It can decode j2c (simple codestream), jp2 & jpc files.
And when linked with GDAL it can read GeoJP2 tags embedded in jpeg2000 picture files.
I've tested the plugin with Netscape / Mozilla / Konqueror / Opera (very beta support)
The license for the plugin is GNU v2, Jasper has it own licensing terms and GDAL is released under an X/MIT style Open Source license.