Hey, I can answer this one!
Yes, there is a CMS and it is a really good one.
MamboServer is a great CMS and there is a module that has a reciprocal link exchange called
Link Exchange Component. Now I know Mambo is good but I have yet to fully test Link Exchange so I don't have an opinion on it.
On the downside, the ENTIRE development team for the [free and open source] Mambo left in a dispute with the sponsor and original developer of the product. They have started with
Joomla which at this point and time is the same as Mambo but who knows how well this fork will do [but I suspect that Joomla will suspercede Mambo over time].
Hope this helps!
---art
P.S. One last thought. Mambo has a "wrapper" function which allows you to add ANY web page to the CMS menu. If you use a separate link list program, you could code it to match the CSS of your Mambo site and it would appear seamless to the surfer and fit right into your site.