What separates the "redmine" from "megaplan" and "bitrix24"?

Added by Иван Иванов over 1 year ago

"redmine" is anything different from "megaplan" and "bitrix24" or is it the same thing, only the interfaces are different?

If anyone wants to see these systems:
bitrix24
site - http://b24-n877fy.bitrix24.by
login -
password - 12345678

megaplan.ru
site - http://mp27280653.megaplan.ru
login -
password - 12345678

PS
I just learn programming, so I can not correctly formulate questions.