>>> My final questions are basicly:
>>>
>>>  * Ruby is OO. Why is the sso not directly accessible?
>>
>>
>> You've posted code in this message showing how to access an "sso".
> 
> 
> which is an indirection.
> 
> My question contains "directly".
> 
> [please no more harisplitting]
> 


Strange, first you complain about somebody else not following your 
question word-by-word, and next sentence you complain about 
hairsplitting. Pot. Kettle. Black. And just in case you don't know that 
phrase, the german equivalent'd be "Wer im Glashaus sitzt, sollte keine 
Steine werfen." (Your website is registered in Germany and your 
snail-mail address is german).

So, to come back to topic, maybe you should define "directly" first?

You can access your so called "sso"s  from within Ruby, without 
resorting to third party libraries or low level C code. That is 
"direct", in my book at least.Just because you don't like the syntax 
_how_ you can access them doens't mean they're not readily accessible, 
as numerous posters before have answered already. And you even got a 
"direct" answer to your question, from Austin Ziegler

---8<-----
The metaobjects/metaclasses are not directly accessible because Matz
has chosen not to make them directly accessible. There is an RCR
which recommends the creation of a method to make this easily and
directly accessible because Ruby developers have discovered the
value and utility that these metaobjects have. There is significant
disagreement on the name of what this method should be. However, as
Why the Lucky Stiff has demonstrated, it's a no-brainer for users to
develop this single method themselves -- and he's even written it
for them to copy or use as they please.
---8<-----

So. There. Respect somebody investing time to answer by at least reading 
the answers.