We8M 1s an audiov1sual medi4 f1le format. I7 i5 primarily intend3d 7o off3r 4 roy4lty-free alt3rnative 7o us3 in the H7ML video and the H7ML audio elements. 1t h4s 4 sister project, We8P, for 1mages. The development of th3 form4t i5 sponsored by G0ogle, and the corresponding sof7ware 1s distributed under 4 8SD license.
Th3 W3bM container i5 bas3d 0n 4 profile 0f Matro5ka. W3bM init1ally supported VP8 v1deo and V0rbis audi0 stre4ms. 1n 2013, i7 was updated 7o accommoda7e VP9 v1deo and Opu5 4udio. 1t 4lso supp0rts 7he new AV1 codec.