SIP Witch, Skype and cell phones...

[Linuxguy123]

On Tue, 2010-03-16 at 14:30 -0430, Patrick O'Callaghan wrote:
> On Tue, 2010-03-16 at 11:19 -0600, Linuxguy123 wrote:
> > Could someone explain to me in plain english what SIP Witch does wrt
> > to Skype ?
> 
> Skype doesn't use SIP as it has its own proprietary protocol, so I
> wouldn't imagine it does anything.

Thus my question.  The web page states this:
=========================================================================
This feature enables an entirely free software alternative to Skype
using standard IETF protocols along with support for direct peer-to-peer
secure communications such as possible with ZRTP capable softphones and
without need for a mitigating "service provider"
=========================================================================

Is SIP Witch a Skype server ?  Ie can Skype phones connect to it and
then it makes a SIP connection on there behalf ?

Or do they mean it replaces Skype as a way to make a call using VOIP ?

I'm confused as to what it does and I can't really find doc on it that
explains things at that level.

"GNU SIP Witch also is being introduced as a desktop VoIP mediation
service to enable the construction of participatory bottom-up secure
calling networks and to enable replacement of Skype with free software
and published protocols."

http://www.gnutelephony.org/index.php/GNU_Telephony

Does this mean I can be my own SIP provider ?