From things you always wanted to know:
I recently
read that there are 5611 free .ch domains of 26^3 (17576) with three letters.
I thought this might be interesting for .de too. I wrote
a small script to automatically
test this and the output this morning is:
...
checking zzy.de
checking zzz.de
17576 possible domain names -114=1762, 0 free .de domains
-114 is for domains you can't register for example because some of them are country codes.
Interesting result I think, there is no free .de domain with 3 letters.
Damn domain grabbers!
The script uses output by whois so if you want to use it, be sure you use the same whois version I do (GNU whois 4.7.21).