After going through 7  Betas of testing first Firefox 5 Release Candidate now available for download and if you’re on Firefox 5 Beta channel you’ll be notified about release candidate update automatically with in 24 to 48 hours  or you can manually download from Firefox Beta channel page.

What’s new in Firefox 5 RC1

  • Added support for CSS animations
  • The Do-Not-Track header preference has been moved to increase discoverability
  • Improved canvas, JavaScript, memory, and networking performance
  • Improved standards support for HTML5, XHR, MathML, SMIL, and canvas
  • Improved spell checking for some locales
  • Improved desktop environment integration for Linux users
  • WebGL content can no longer load cross-domain textures
  • Background tabs have setTimeout and setInterval clamped to 1000ms to improve performance
  • The Firefox development channel switcher introduced in previous Firefox Beta updates has been removed

Read Firefox 5 RC release notes and complete list of changes in this version.

Source : Mozilla Developer news