test: header 1 
#f
# f
test: header 2
## foo
test: header ends with ' #'
# # # 
test: header ends with '#'
# foo# 
test: 6+ #s is not a valid header
####### foo
test: # followed be only space is a valid header
# 
test: only space between #s is a valid header
#  #

# test links  [Cloud9 IDE](http://www.c9.io/) #
* [demo](http://ajaxorg.github.com/ace/) [+](escape(\) ) [+](a "title") [+](a "space" )
* usually *work* fine (_em_)
in lists

in plain text <b>http://ace.ajaxorg.com<b>