I am not sure whether ACSM actually looks at individual programs and endorses them or not but I found a position paper by ACSM which recommends plyometric activities for children. Here is the link: http://www.acsm.org/docs/current-comments/plyometrictraining.pdf
The images I have seen of CrossFit make me not want to recommend it to anybody but that was (hopefully) a misrepresentation of that program. It is always important to make any program fit the participants and not the other way around.
Hope this helps.
You might want to visit www.acsm.org and do a search on their site for Cross Fit to see if you find anything.
The ACSM site has plenty of resources.