I think p2's competance is in its front-end. I own no Maru or P2 account, but I see
many users of smartphones, PDAs, and other limited ability devices answering question
"what's the best 2ch browser on this?"with "I'm using official P2". so I guess it just
works on any device in any OS, as an ASP. That's important, because there're some
2ch board difficult to browse and navigate directly through web browser, and sometimes
people gets their ISP temporallily banned and want to get around it, and sometimes they
want to write through anon proxy. Definite reason why P2 and Maru coexists are not in
my knowledge, maybe just because they have different origin. anyway these things do
happen in 2ch.