My favorite is X11's select-to-copy, middle-click-to-paste feature. It bewilders me that this isn't standard on all platforms. It only takes two simple clicks to copy and paste, yet some people find it unintuitive (or even downright hate it). I think it's a huge time-saver.

This was instantly what came to mind for me, followed by tab completion in the shell (expanded by the bash-completion package to become utter perfection).

Tab completion is a good one! According to Wikipedia, "one of the first examples appeared in the Berkeley Timesharing System for the SDS 940" (http://en.wikipedia.org/wiki/Command-line_completion).

Utter perfection is unfortunately limited to ZShell's bash completion, but I know what you mean - I experience it every time I log into a Solaris box and have to use CSH.

Don't get me wrong, Cshell is good too syntactically speaking, but the completion on Solaris 8 is a little, meh.

BTW - we have a dojo with different versions of Solaris going back to god knows when, that's why I'm using CSH - would not use Solaris 8 in production anymore.

I knew they wouldn't have mentioned my two favourite Amiga OS features: Pre-emptive multitasking and the Workbench screen model. At a time when PC users were still struggling with blocky DOS screens, the Amiga offered a virtual desktop type environment through workbench screens (which could be dragged up and down over each other or flipped backwards and forwards) and proper multitasking meaning that things in the background screens would carry on running.

The other OS feature is one that I only started playing with a couple of years ago on the ZX Spectrum. The ZX Spectrum has a fairly unique way of drawing the screen in monochrome 256x192 pixels and a 32x24 8x8 pixel colour attribute cell system. Ignoring the monochrome (which was what I used to use in the 80s) and manipulating 8x8 cells directly means that the entire screen is represented by 768 bytes of memory. This lets me play around with colourful 3d in ways I could only imagine as a kid. Sad, I know, but I'm just a big kid in the end.

Amiga is one of the big OSes I never got a chance to play with, though I know it had some innovative features and very loyal users.

Other than finding an old Amiga, is there a practical way to give it a try today?

You'll need an emulator called UAE (http://www.amigaemulator.org/) or a port like WinUAE (which comes with a frontend and is much easier), a Kickstart file for the right system (Kickstart is the name for the Rom and varied from Amiga to Amiga) and some floppy disk images for the games themselves. There's a WinUAE guide here: http://www.tweakguides.com/Amiga_1.html and a more general beginner's guide here: http://cpc464.back2roots.org/menu.htm

It's very different to modern OSes if you don't tweak around but as a modern alternative the Icarus AROS distribution (http://www.icarosdesktop.org/) provides a modern continuation of the Workbench experience.

Outstanding. I will give this a go ASAP.

PS: I'm the author of this article. Had a great time thinking about all the fun systems I've played with over the years and researching their history.

Don't get me wrong, it's a good article and I enjoyed it. Props for mentioning BeOS, $deity bless her and all who sail in her ;)

No worries. I love the feedback. Fodder for a second installment? Keep the ideas coming.

Ok, in no particular order:

* Built in BASIC on the Commodore PET

* Folders in MS DOS (CP/M didn't have them)

* The trashcan in Macintosh System 6

* The start bar in OS/2

* I can't think of a single unique thing about Atari TOS

* The stability of Windows 2000 (compared to 9x and NT)

I'm not sure how we want to define "OS feature", but Spotlight is amazing.

package managers like Apt and Arch Linux's pacman.

Absolutely. "Oh, I need <insert obscure file> to compile this?" apt-get and 15 seconds later, I'm good to go.