VLC Media Player will play all MP4's perfectly on Linux, OS X, and Windows.

https://www.videolan.org/vlc/

I removed Real Player and am now enjoying the VLC Payer!

Yeah, VLC Player is so much better than Real Player.

I use a stripped down version of Debian Linux on an old IBM Thinkpad laptop with VLC as a portable media player. It will play anything I throw at it from old avi's to new mkv's and mp3's to ape files.

It is a great little application.

And you... If VLC won't play it, it's proprietary, and you need whatever the vendor wants you to use.

I do my best these days to avoid as many proprietary formats and applications as possible.

Even on Windows, I use Open Office, GIMP, Inkscape, Scribus, Infranview, VLC, Miranda & Pidgin, PostgreSQL, Clamwin, Audacity, VLC, 7Zip & Peazip, ImgBurn, Sumatra PDF, and NotePad++. I also use as much as possible small developers' applications over the big corporations. I much prefer Sagan Metro for midi & hard disk recording then I do Logic or ProTools. I love developing with PowerBasic, Squeak, and SWI-Prolog.

It took me a few years to make the switch, but it has been worth it. And these days, I rarely have any compatibility issues.

Like handbrake, cdburner XP and audacity.
The more people who use these open source programs, the better!
And if you HAVE to buy software, buy shareware, because the money goes to the developers, not the corporations!

Yes, I listed audacity. I never had a need for Handbrake, but it is an excellent program from what I have seen and heard. I prefer ImgBurn but it always nice to have options, isn't it?

I definitely believe in supporting developers directly through shareware. I would not be able to continue my development without users purchasing directly from me. I stopped developing for Apple when they force me to go through their App Store and give up a percentage of my profits for no real good reason other than they want complete control of the ecosystem.