Portal blog aggregating other “clients” blogs… RPC or RSS ?

Hi,

I’m searching a solution to aggregate 3 or more blogs to one main (portal) blog. I’d like to have a portal blog that always show the last entries from the other blogs (like A to C in the ascii art below).

[PORTAL]<—– get the last entries from A to C
/’ | ‘\
[A] [B] [C]

I think, there are 2 solutions
– pingsback (via the update services – the cleaner and fast way)
– a rss aggregator in [PORTAL] (means polling ?!):

I’m searching a GPL RPC server (for the portal) that I can put in the “updates services” of all my blogs (A to C in the example)… pingomatic and others search engine are doing this but they don’t give source code (or I’m blind ??

An other way is reblog.org… but I’m not sure it will do the trick for me.
https://www.reblog.org/wp/
https://projects.radgeek.com/feedwordpress

I hope someone have the magic answer ??

PS: I don’t know if I post in the right category. If not tell me I will repost in the “Miscellaneous” or “Plugins/hack”

Thanks
Tom