"Boycott all SEA products!! Long live Phil Katz."

And don't forget that 7zip (the application, not the format) is better ad making zip archives than winzp and better at making rar archives than winrar.

In the end it doesn't really matter anymore. Most programs nowadays can open more than one type or archives, and zip, rar and 7z are most used anyway (with addition to tar, and gzip on Linux)
When preparing something for a pure DOS environment, it has to be unpacked anyway. That can always happen before bringing it to DOS. No matter if will be transported via network, floppy, usb, etc.

I usually use 7Zip on newer and older systems, because Winrar and WinZip do have those "Your Time expired buy Winrar now!" warnings, so i kind of use 7zip everytime even on older systems, because i became attached to it.

Osprey wrote:

I have fond memories of PAR from the Usenet days. I don't remember if it applied its own compression algorithm, but it was an archive format that was great for recovery. I miss being able to reconstruct missing volumes that I couldn't download.

PAR files are unrelated to compression. Parity (i.e PAR) files are used to replace missing sections of data. This applied well to usenet where frequently subsets of messages may go missing.

I keep hoping to see a return of the concept of PAR files for torrents. I imagine that distributing a few parity files amongst a swarm of downloaders would cost almost nothing in the amount of download data, but would greatly reduce the chances of torrents breaking when a seeder went away.

Quite frankly only very occasionally have I found myself in situations where I needed to get a Win9x/DOS environment working from scratch without the aid of a period software archive, and that's where plain .zip's proved a better choice, but any use of .zip beyond that I don't think I could justify in 2018.

7zip's hands down the best "usable" compression in town, but as a long time .rar Usenet dweller, I think I continue to unconsciously perpetuate the notion that this format may be more resistant to hijacking and integrity failures, which thing may or may not be true today, but it certainly was back then, so a thousand pieced .rar's each split into a thousand yenc's....

Do you think it's worth using RAR4 compression?

When it comes to compressing files for my own personal use, I always go with the latest and greatest WinRAR (I'd say it's a tradition at this point), but if I'm to share something online, there's a good chance someone will not be able to open it, so I go .7z. RAR5 has a few notable advantages over RAR4 and there's no reason for me to take that step backwards, so I guess it all depends on what you're using it for.

Of course I got them mixed up - I thought RAR4 was the latest.