Most notable with Firefox 145.0 is 32-bit Linux support being dropped . Firefox 144 and Firefox 140 ESR are the last series with 32-bit Linux support so Mozilla can focus solely on 64-bit.
Exciting some with Firefox 145 will also be the long-awaited enabling of Matroska support for commonly used codecs including AVC, HEVC, VP8, VP9, AV1, AAC, Opus, and Vorbis.
Plus there are numerous developer additions with Firefox 145.
Firefox 145 release binaries can be downloaded at Mozilla.org .