If this is true then there are a lot of misinformation about the project. It's a great difference between 1 and 7 active developers!!!
the active developers are what i mean by the "main ones." so i see 2 or 3. the reason for the "or" is that there are a number of sub-projects under LIMXTEC which all support the Bitcore ecosystem (for example the bitcore-lib-btx mentioned above is a sub-project), and each contributor to those subprojects can have their own bitcore related subprojects in the works which have not yet been added to the list of LIMXTEC subprojects. I went ahead and further analyzed this, without going into each contributor's subprojects, so the below doesn't reflect any work done which has not yet been merged or accepted into the deployed code.
the main project (i.e. the "core" project) that I see is this one :
the subprojects that I see are these (note the contributors listed are those from the project that these subprojects forked from, so only bitcore developers which contributed to the main branch are relevant) :
so it looks to me like there are 4 active developers on the project, at the current time. This is open source so new people could add themselves and others could fade away, so the number of active developers at any one time is not set in stone.