@you two^

"Also lightfrog is deadly imperformant as it uses simple shadow mapping with 6 views per shadow map (image your game takes about 6 times additional render time PER light)"

yes, yes and no.
It is slow and it does use 6 views for shadowmapped pointlights but even the newest engines use this approach because it's simple, fast (through clever culling and similar stuff), easy to blur, etc.

With an engine like acknex, however, performance is pretty bad due to the slow-as-fuck rendering and rather small freedom for optimizations.

If you think 6 views are too much you could use dual paraboloid shadow mapping (2 sm. views) but this results in badly distributed pixel density and higher performance cost because of culling reasons.