The JP2 image format is an image file extension which is not very common as yet. You could view the Jpeg 2000 as the next generation of file formats that will come as the JPEG 2000 has many advantages over the normal Jpeg format.
The format was introduced in the year 2000 which is where it gets its name from. The Jpeg 2000 much like the Jpeg format is used to compress picture files. The Jpeg format has been used for many years and has good compression however the format does have a short coming in that the quality of the image suffers from the compression. The picture quality deteriorates the more you compress the picture file.
The Jpeg 2000 format compresses the file even more however unlike the Jpeg the picture quality does not deteriorate as much as the normal Jpeg compression. The trend today is the the most users of these format are Botanical websites and website which use high-resolution images such as geological websites.
The disadvantage so far has been that not many people have used the new format as that there is currently a lack of software development for the new standard. Most of the development taking place has been at universities. The links for NASA shows to the increased use of the format for viewing space pictures. You can see the Jpeg 2000 view software on this website for Linux, Windows as well as the Mac OS.