@Manuel: you're replying to FiXato I assume (some other guy posted something else in the meantime 
) Yes, it's a feat kinda, but I think you *have* to use Chrome/Chromium here. Seems FiXato is using Regex functionality that has not landed yet in Firefox (named capturing groups). Options for @FiXato: use Babel or simplify regex (looks overly complicated (for its purpose) ?) and/or don't use named capt. groups (shouldn't be too much of an issue to adapt using regular capturing groups instead).
Thanks ren 
I hadn't noticed the replies about it not working in some browsers till I worked on the player again today while implementing support for NicoNico (nicovideo.jp).
I've replaced the named capturing groups for regular index captures, and it now seems to work in Edge as well.
I'll go through this topic and add a bunch of NicoNico video examples that have been mentioned here. Should be added in an hour or so to https://fixato.org/music/player/msx-related.html
(Edit: videos/songs sorted and added to current playlist.)
Hmm.. after some songs the indices no longer seem to match with the actual playlist entries...
Will have to see what is causing that. I'm guessing an unfortunate e
side-effect of a recent change that prevents duplicates, probably not playing nicely with playlist expansion...
Hopefully I'll find some time today to fix that.
Edit: I think I got it fixed now.
Edit2: I have also made a version that should work on IE11, but it needed too many changes for it to be worth it to maintain it (or to convert my ES6-dependent Javascript code to legacy/compatible format). So, consider this a legacy version that might break further down the line. :) I might care about old homecomputer systems and consoles, but when it comes to outdated browsers, they can take a wrong byte and choke on a chestnut. ;)
Meanwhile, the regular version should work fine in modern browsers, even in Microsoft Edge. *eyes Meits*
Edit 3: Added support for loading your own JSON-playlists by specifying the JSON file's URL in the playlist parameter.
See this example JSON file for the format.
(Basically it is a hash/associative array in the form of {"URL": "description to be displayed in playlist", "URL2": "description for the second song"})