InfraRecorder (Windows)
InfraRecorder is a free, open-source CD and DVD burning application for Windows. InfraRecorder covers almost any of your optical needs, including support for burning disc images, copying discs, creating quick audio CDs, writing video DVDs, erasing discs, and more. InfraRecorder is lightweight and decidedly bloat-free, and it's even available as a portable app you can carry on your thumb drive to satisfy your burning needs no matter where you are.
ImgBurn (Windows/Linux)
ImgBurn is a free CD and DVD Swiss Army knife for Windows (it also runs on Linux under Wine). ImgBurn can write data from a variety of formats, burns audio CDs, ISOs, and video DVDs, including regular DVD, HD DVD, and Blu-ray DVD. As an added bonus, ImgBurn can read a disc to an image on your hard drive and build a disc image from files on your computer. It's fast, easy to use, and doesn't cost a penny. Incidentally, this app is still actively developed by the same developer who built the once very popular DVD Decrypter.
K3b (Linux)
K3b (which stands for KDE Burn Baby Burn) is an open-source burning application for Linux. Like the rest, K3b supports common tasks like burning audio CDs, data discs, disc images and disc copying. For movie lovers, K3b can even rip your DVDs to your hard drive in either of the popular DivX or Xvid formats. If you're running Linux, K3b is easily one of the most popular options for burning anything to your optical discs.
CDBurnerXP (Windows)
CDBurnerXP is a free authoring software for Windows. Despite its name, CDBurnerXP works with Windows Vista, 2000, 2003 Server, and XP; it also burns to CD and DVD, including HD and Blu-ray. It's got a small footprint, and like most of the other options, burns data discs, audio CDs, and ISOs without a hitch. CDBurnerXP is light, fast, and free, requires .NET 3.5.
Nero (Windows/Linux)
Nero 9 is a shareware optical media authoring tool for Windows that's long been the go-to favorite for robust, user-friendly CD and DVD burning for a price. Detractors complain that Nero is slow and bloated (and the 370MB download, 2GB free space requirement, and long install time doesn't inspire confidence to the contrary), but fans argue that you can install only what you need from Nero and that its simplicity more than makes up for the bloat. Nero 9 is an $80 shareware (grab the trial here), Windows only, requires .NET 3.0. Linux users can give Nero Linux a go for $25. [via life hacker]