Do people still use the K-Lite Codec Pack so their players have all the codecs installed? Or just use vlc?

I loved the K-Lite Codec Pack and CCCP (Combined Community Codec Pack) back in the XP days, especially while exploring MKVs and anime, but I virtually never run into a media file that VLC or MPC-HC can't play by default these days. Just drop it in and it plays.

If I understand correctly, most of what K-Lite / CCCP did was wrapping libavcodec/libavformat for the Windows APIs, so native players could use them. VLC just ships with libavcodec included, so it supports all these formats. Not sure about MPC-HC nowadays (it used to use Windows APIs, but you’d usually get it with your codec pack installer anyway).

K-lite originally was a giant mess of stuff that gradually got pruned down as the libav-based things got better and covered more of what was needed. These days it's just mpc-hc plus lavfilters and a few incidental tools.

I still use K-Lite since they ship MPC-HC (a fork of Media Player Classic) that comes with really good HDR support and default configuration out of the box. If you don't like to have the desktop in HDR you can even configure it to automatically toggle on/off HDR whenever an HDR movies is played.

The HDR support in VLC has been really lackluster. Maybe it is better nowadays, I don't know.

It stopped being a thing about 10 years ago.

Mostly because everything is H.264, H.265, VP9, AV1, MP3 or AAC.

These days you can just install SMPlayer and have all the codecs bundled in the player.

mpv