For normal use we recommend installing TeX Live over the Internet or from DVD, but if you want to burn your own DVD, you may want to get our huge ISO image. It is over 2GB (md5, sha256 checksums). You can:
If you want to mount the image to make the contents available for
installation or browsing, a typical invocation on Unix is:
mount -t iso9660 -o ro,loop,noauto /your/texlive2015.iso /mnt
On Windows, you'll need third-party tools such as WinCDEmu, daemon-tools, or Magic ISO.
After mounting the image, to install TeX Live, follow the installation instructions or read the documentation, which has a section on ISO installation.
The ISO image is not updated after release, so that it can serve as a stable marker in TeX development and to correspond to the DVD sent to TeX user group members.
Sources: the ISO includes the complete sources in the source/ subdirectory, corresponding to Master/source in the repository.
The ISO image is also available as texlive2015.iso.torrent. Start it with your favorite torrent client.
Please, after downloading the full torrent, keep the torrent client running for some time to seed the files so that the files get better distributed.
Information about other ways to acquire TeX Live is available separately.