bleeding edge

Short definition from Wiktionary

Noun

1. 1
   The situation produced when the image extends beyond the nominal margin.
2. 2
   Something too new and untested to be reliable or to have any assurance of safety; the figurative place where such things exist.
3. 3
   Alternative form of bleeding edge.

Adjective

1. 1
   Of or pertaining to something, such as technology, which is too new and untested to be reliable or to have any assurance of safety; (in a weakened sense) that represents the latest developments in something.