The central web servers are set up to execute every file found in /cgi-bin directories unless its file extension is listed in a special list of exceptions shown below.
NOTE: This is about to change fairly soon (September 2009) and emails have been going out for a few months to any admins who might be affected (those who use scripts without file extensions). When the change occurs, the behavior will be flipped. Instead of executing every file unless its extension is on a list of exceptions, no file will be executed unless its file extension is on a list of file types that are executable (such as .php, .cgi, .pl, etc.)
gif
jpeg
jpg
png
ico
swf
avi
m4v
wmv
flv
css
js
jar
shtml
shtm
html
htm
xhtml
xhtm
xml
txt
pdf
mov
doc
xls
ppt
pps
odt
ods
odp
docx
xlsx
pptx
mp3
wma
