Consider these alpha releases: they are being heavily updated to work with the newest Seaside (3.0a5 currently) and to sort out compatibility with different platforms. With that said, though, all of the Pier tests and all but four of the Magritte tests pass, so give them a try. You'll need the B130 development build of VA Smalltalk.
The original Pharo sources for these Seaside 3.0-compatible versions are available: pier repository magritte repository. Again, these packages are still in flux. They're now built on top of the same Grease portability layer as Seaside 3.0a5; I'd encourage interested platforms to give them a try and see how easily portable they are.