Twitter is a walled garden. Laconi.ca isn't, you can subscribe and respond to users on laconi.ca installations on other domains. It doesn't even have to be run

Twitter is a walled garden. Laconi.ca isn't, you can subscribe and respond to users on laconi.ca installations on other domains. It doesn't even have to be running the laconi.ca software, you can communicate with any domain which adheres to the OpenMicroBlogging protocol (there is atleast one other implementation out there).