This link contains the timeline of all the server projects since the first prototype until now http://timeglider.com/timeline/ba816dfbf2acee562164

It's lcdr or DLU, we can't measure exactly what is the must progressed project even we can't measure the progress in the worlds due to some reasons I will describe later If we measured the progress by the testers amount we would say that DLU is the most progressed though that the amount of the active testers of DLU is almostly the same of the total testers of lcdr but we can't say that some project from 2 these projects is the must progressed because only the devs know the exact progress