Finally, a decent Flash frame­work for Infor­ma­tion Visu­al­iza­tion is avail­able: Flare is an off­spring of the Java-based prefuse toolkit, writ­ten in Action­Script 3. Espe­cially notable is the good sup­port for ani­mated tran­si­tions, an impor­tant topic in inter­ac­tive visu­al­iza­tion. Flare is open source soft­ware licensed under the terms of the BSD license, and can be freely used for both com­mer­cial and non-commercial purposes.

Thanks to Till for the tip!