title_body: Are Interslavic and Neoslavonic the same conlang? I read that Interslavic and Neoslavonic merged into a single language.
  
  All three projects collaborated closely with each other from that time, and in 2011 Medžuslovjanski („Interslavic”) was chosen as a common name. Fruits of this cooperation were, among other things, a common dictionary, a common news portal and a common wiki.
  
  I wonder why there are two websites:
  
  Interslavic – Medžuslovjansky – Меджусловјанскы,
  interslavic language tutorial with the domain name &quot;neoslavonic.org&quot;.
  
  Is there any difference in the grammar? If so, which one is the most popular?
upvoted_answer: Depends on how you look at it; the Interslavic page does say (as you have noticed) that:
  
  
    All three projects collaborated closely with each other from that time, and in 2011 Medžuslovjanski („Interslavic”) was chosen as a common name. Fruits of this cooperation were, among other things, a common dictionary, a common news portal and a common wiki.
  
  
  -- History of Interslavic
  
  Thus, historically speaking, they are two different projects (plus a third one) that have coalesced into one, and are now one project with some internal variation. The websites are continuations of their individual parent projects, as each team retained its independence from the new fused project.