So, first, I would not look at any Wikis for these philosophies, but instead check out their official websites:
https://www.amshq.org/Montessori-Education/Introduction-t...
http://www.whywaldorfworks.org/02_W_Education/index.asp
http://www.reggioalliance.org/faq.php
Here is a comparison which I think is pretty on target:
http://www.pbs.org/parents/education/going-to-school/choo...
So, here's the thing-- I have worked in quite a few child care environments and am familiar with all of these philosophies. I would say that you know your child best... some of these philosophies will suit a given temperament where others might not be a good match. Add to this that some centers which label themselves with these titles (add 'constructivist' as a philosophy very similar to the Reggio model) might have different priorities than the true, strict philosophy, and some may or may not have teachers who have studied the philosophy, but who are loosely interpreting it. (There you have the 'waldorf-inspired', etc. One preschool I sub at where my son went describes themselves as "Waldorf and Montessori inspired", which is what my preschool was as well, although mine had a firm base in emergent curriculum and also followed Reggio traits as well.)
Much of what I would suggest looking at is not just the philosophy, but also the teacher's level of education in that particular philosophy, years of experience.... how does the environment *feel* to you as a parent? I knew one teacher who narrowly interpreted Montessori as having only 2 or 3 activities out for the children to use at any given time, which caused stress for the children. (this was not at a Montessori school, btw) I know of very regimented Waldorf programs which insist that families not allow television or screen time for their children and which embraced Waldorf as a family lifestyle and not just as a teaching philosophy limited to preschool.
All this to say, this is one of those times when you really want to go with your gut. I encourage parents to check out programs in person, see what the 'tone' of the group is. I would say it is less about the philosophies and more about the teachers and the child, to be quite honest. If it feels like a good match, if the teachers are warm with the children, receptive to their needs, if their program feels like there is depth and structure with a concerted focus on helping the child develop socially and emotionally as well as intellectually-- those are all things to look for, mainly because if children have support in these realms, the rest of their learning usually comes more easily. The preschool experience is 'grounded' for them by teachers who ensure the environment feels manageable, safe and available for them to explore. If those realms of social and emotional support are not in place, even if everything else is, children are less likely to thrive and learn, because developmentally, between 3-5, this (social/emotional) is where the core development is naturally taking place.
I hope I gave you some good references and that this helps you a bit. As someone who appreciates 'what's good' about all three of these methods, I am more concerned about the actual staffing and who my child will be in contact with throughout the day than I am the philosophies, which can be interpreted as loosely or stringently as the director and teachers see fit.
ETA: and, as Mamazita pointed out, the NAEYC accreditation can be very helpful. There are good programs, too, which are not accredited through this association, but for larger CDC (child development centers and preschools) this is a good sign that the center wants validation, oversight and review. Be sure to ask how 'old' the accreditation is, though-- I say this only because I did work at an NAEYC certified CDC and in the course of two years, we had two directors who made poor hiring choices and the quality had gone downhill. :(