How was this site developed?

[projecttoday]

I would like to know if there is any way you can go to any web site on your computer and know what it was developed in, like PHP or ASP.Net or Ruby or whatever, just from going into the sight. If not, are there clues that might point in one direction or another?

[evstevemd]

Check extension (If it is appended on URL). asp and aspx, php or check the aplication (if you can recognize). This site is likely made by VBullets.

[digital-ether]

Try using builtwith.com. It tells you a lot about the technologies websites are built on.