Hmm... http://twister.net.co/ maybe? The biggest issue is going to be mobile, but if you have enough people firing it up on servers and stuff, you'd probably be okay. And then of course you realize that there's also the even bigger issue of actually getting people to use it. You're fucked there unless you have some serious marketing talent, which most people capable of writing such a thing in the first place lack.
Most people don't care one way or the other. They just want it to do what they want/need.
The only thing twitter does better than basically anything is:
Has a giant userbase containing many influential Internet celebrities.
Except for that it is inferior in almost every single way, starting with the ridiculously low character limit, continuing with the spam everyone all the time etc the list goes on.
Hey, even google+ is better in several ways, except for the part about Internet celebrities.
On spam, I don't know what you're talking about, because I get no spam. I'm @alexelcu on Twitter, my account is from 2008 and I'm counting about 20 blocked accounts corresponding to about 20 spams I got in 8 years, which is actually rather impressive.
I think people complaining about the char limit don't understand the value of Twitter.
And no, Google+ seriously sucks, I could rant all day about how much Google+ sucks. And you know what? Google+ wouldn't need Internet celebrities if it would be compatible with the open Internet, but it isn't ;-)
It's an interesting form of spam, which isn't trackable by observing Twitter message traffic as it lives entirely in account metadata.
When it works you find out things you didn't know you were interested in - getting out of the 'filter bubble'.
“I believe we need to build a platform that respects and amplifies every voice in a way that the world needs to hear it. I trust that the world will amplify and retweet and have conversations where appropriate.” [1]
Which means "Kill the cops" is ok but "#StopEnslavingSaudiWomen" gets your account banned. [2]
[1] http://www.breitbart.com/tech/2016/06/02/jack-dorsey-blms-de...
[2] http://www.breitbart.com/tech/2016/09/21/twitter-suspends-wo...
[1] http://www.politico.com/blogs/media/2015/05/clinton-foundati...
If they remove all the fat making a tweet page 5mb it could be hosted for nearly nothing by some FOSS org.
It's one thing to build a very small Twitter clone for you and your friends, it's quite another to scale that up to hundreds of millions of users and keep everything running smoothly.