The emulator was an interesting thing. Good for beginners to test out the commands.
Perhaps you also should make a small guide about how to get a low end VPS to play around with as well, lowendbox.com usually has many good offers. Or even how to set up for example vmware and install a linux version on it on the users own computer.
I liked the site, but you had to scroll a lot, what about being able to collapse/uncollapse the various sections? By clicking on the header of a section, you could collapse or uncollapse that section, and perhaps also a selection for viewing everything in flat mode.
The download link http://learningunix.com/Teaching/Unix/units-1.74.tar.gz appears to be dead.
To add some spice to the site, you might as well add a shoutbox, or a feedback box, to add some interactivity on the site.
You might also consider throwing up a multiple choice test the users can go through after having finished the tutorial, and perhaps there could even be a high score list! There could be lots of questions, of which a subset is presented for each multiple choice test.
Good initiative.
This is great, constructive comment, thank you very much
I am not author of this emulator, as you can see there is only a link to other website.
I was thinking to create accounts for interested users on my server, but I am afraid of abuse.
About other suggestions, I will take them into account. Maybe even add some of them this weekend.