Looks like 6.17 is newer than 6.7. Is this correct? If so what is up with the numbering scheme?
It’s just Mikrotik’s backward way of doing numerous things…
six.seven is older than six.seventeen
Only Star Wars gets numbered 4-5-6-1-2-3-7.
What you thought about would have been written 6.1.7, which is not the case because there is no dot…
all software is numbered this way. linux kernel, MacOS etc.
these are not decimals
6 indicates major release 17 indicates minor version
No, not all software is numbered this way. Fortinet, Sonicwall, Cisco and many others do not use this limited scope. Mikrotik’s version numbered 6.7 should be 6.07 or 6.0.7 to denote a minor revision. Likewise 6.17 should be 6.17 or 6.0.17. This also makes it hard for many file systems to sort them numerically as well. Without a leading zero in the minor releases this is needlessly confusing as different manufacturers may use endless point releases as retail upgrades. see: OSX- still on version “10” after 15 years.
(remember: I’m not english, forget my syntax error, please)
OBVIOUSLY 6.7 can not be greather than 6.17
Without any other point, is logic version number can not be a decimal number!
And is also obvious (an not noticed) on the download area are present last version…
Let see…I think not every system is numbered this way 
Windows 1, Win 2, Windows 3, Windows 3.1, Widnows 3.11, Windows 95, Windows 98, Windows 98SE, Windows Me, Windows NT 3.5, Windows NT 3.51, Windows NT 4, Windows 2000, Windows XP, Windows Vista, Windows Srv 2003, Windows 7, Windows Srv 2008, Windows Srv 2008R2, Windows 8, Windows Srv 2012
It is easy to understand major.minor numbering scheme but you are right that sorting could be a bit cumbersome.
To be clear, when talking decimals - the OP is kind of correct (at least in English as we were taught, I understand EU and local languages might be different).
Since it is technically written as a ‘decimal’, 6.7 would actually represent 6.70, vs 6.07 in normal numbering/math. The first number after the decimal is always the tenth, so 6.7 would be 6 and 7/10, vs 6.17 which would be interpreted as 6 and 17/100, making 6.7 a bigger number than 6.17.
In any case - once you know its not hard to live with, still a simple concept, the number increments. Not worth changing at this point in time.
I get the confusion, but how to solve.
Let’s assume the versions are written with leading 0 (6.07 → 6.08 —> 6.17)
What happens after 6.99???
How many leading 0 is enough?
MacOS 10.9 and now 10.10. What to do now, everybody must be confused!
There is no solution - it stays how it is. My post was simply to point out semantics in decimal numbers. As I said its not a hard concept to grasp so there is no point changing it.
Haha, love it. 
6.100
Just look at IP Adresses: 192.168.0.2. The ‘.’ is just a separator.
The scheme is well known. Changing this scheme would cause confusion.