edmicman's Journal: Where are the open source counterparts to popular web apps?

Open source has given us very competitive alternatives to some commercial powerhouses in software. Office suites (OpenOffice.org vs Microsoft Office), Image editing (GIMP vs Photoshop), web browsers (Firefox vs IE), instant messengers (Gaim/Pidgin, millions of others vs the standard clients), plus a ton of other apps, both standalone and web hosted. But where are the open source counterparts to popular commercial web apps? Specifically, I'm looking at email and image galleries.

Where is the blatant ripoff of Gmail that I can install on my own server that connects to an IMAP server? I want the Gmail interface and user experience, but with my own email server. I looked for something for the longest time that I could install on my host and use as a better webmail client than what they offered. Squirrelmail seems to be everywhere, but using it feels like the Internet circa 1997. Last time I looked, the closest thing was Roundcube, but even that felt simply like a rehash of a desktop email client in AJAX. Gmail's system works, why hasn't anyone copied it yet?

Recently I was looking to upgrade my web gallery from Gallery2 to something else. Gallery[2] and Coppermine are nice, but again, they feel really dated compared to something like Flickr. So where is the the "Flickr" that I can install on my own server? There seems to be *nothing* out there. Why not?