Meklē pēc vārdiņa xmambo
Izskatās, ka "oficiālā lapa" (kaut arī tāda nīkulīga izskatās) ir šeit - http://mamboforge.net/projects/xmambo/
Citāts no turienes:
"... it is modified version of Mambo to allow developers the ability to test XHTML/CSS website designs/layouts while still utilizing the core Mambo features. xMambo will begin it's end-of-life cycle as soon as Mambo releases a major version that produces XHTML-compliant code. In the meantime, I am keeping xMambo's security current to allow developers to test in a more secure environment."