What's the advantage of using RAR's?

Solution 1:

RAR can store file system attributes of NTFS (like streams, full acl permissions, modification/access/etc time, not sure about linux attributes as I prefer tar archives there) and thus makes it a nice complete backup tool with decent compression ability. ZIP can store none of these except plain old simple DOS attributes (read-only, hidden, system).

Additionally RAR supports solid archiving (one compression dictionary for all files) which improves compression ratio if having a lot of small files in the archive. There are also data redundancy and error correction techniques which can be used to fix broken archives (eg broken by transmission errors or bad sectors).

Solution 2:

Zip compression has the ability to break into parts for quite a long time already, so I don't think people are choosing RAR because of that.

RAR does have better compression, but only slightly, and if that is the winning advantage, everybody will be flocking to 7z instead.

IMO, the real reasons why I think RAR is the dominant format now among (coughs-ahems) certain users, are because of a few perceptions:

1. You are a n00b if you use ZIP, and if you use 7z you are too hardcore.
2. It identifies the n00bs when they start questioning how to "un-zip" the files, or what program to use for those "silly RAR files".
3. WinRAR has a better interface with customizable icons, etc. Oooh shiny!
4. You have to pay for WinRAR, and true coughs-ahems users will have a copy somewhere - it's like an exclusive club of sorts, and WinRAR is the membership card.

Welcome to the club, mate.

Solution 3:

I wouldn't say a lot of people are switching to it.

One of the early advantages were that you could split a .rar file into several files so users could download each one seperately, or you could put each one on a floppy disk or CD. RAR also has some better compression than .zip, but I wouldn't call it anything spectacular. I tend to use 7zip for better compression.

One of the common reasons I'll use it is for sending EXE's through e-mail (as i'm a developer). Gmail and Outlook will block .zip's containing executables as potential viruses, and will allow .rar files.

Solution 4:

One big advantage, outside of the users of cough certain classes of users cough, is that ZIP files have traditionally had size limitations -- notably no more than 4GB for the entire archive, and no more than 4GB for any given (uncompressed) file. This issue is resolved with later versions of the format, but you'll still see Windows display error messages when you try to create large archives, even if you're simply trying to compress gigabytes of plain text (which result in tiny files, comparatively).

RAR does not have that limitation.

Solution 5:

After downloading a file (that might have been split into many smaller parts), missing or damaged parts can be recovered by using parity files (PAR files, often in the form of parchives).

The parity file mechanism itself is not at all limited to RAR files. But the ability to split RAR files into smaller parts, combined with the availability of software for RAR/PAR, may have made RAR a popular format for huge downloads, like in newsgroups.

According to Wikipedia version 3 RAR no longer needs such files, as it has its own recovery files. (But I feel this still is not a good reason to use that proprietary format.)