From the linked page:

> The Tab Groups (Panorama) feature will be removed from Firefox in version 45. We know this may be inconvenient and we apologize. Removing the Tab Groups feature will make it easier for us to improve Firefox.

This is plain stupid. How much effort could it be to maintain this feature? Compared to Hello, or Rust, or Servo? None of these are useful to most Firefox users, but tab groups were. How more complex is this than the WebMaker or Persona, stuff that practically no-one uses? Is this harder that writing their current homepage, with blocks, pictures and fancy? I'm not touching a Mozilla product again.