stevenmak
says
想問問大家覺得有沒有那種類型的軟件開發是 close source 賣 commercial license 會比 Open Source 好？
Games
DRM
just thought one more ... PageRank 
stevenmak
says
PageRank 連 algorithm 都 publish 左, open 唔 open 都唔差太遠吧