A straightforward answer to that question is NO! It is illegal to explore Kilimanjaro independently without a guide. Unlike many other treks, it is not possible to just turn up at the foot of Kilimanjaro with a backpack and camping gear and head up the mountain.  Furthermore, Mount Kilimanjaro is not an easy climb, so climbing it with experienced guides is a must not only from a legal point of view but also for your safety.