Detect installed applications (software dev) on OS X Lion I'm a first time Mac user. 

Aside from checking out the installed applications on my Applications folder, are there other ways to find out what applications have been installed on my OS X Lion?

When I tried out the Terminal, and then assumed that the IRB (Interactive Ruby) or Ruby was installed, so I typed "irb" and it did work.  It ran the Interactive Ruby and I was typing simple Ruby commands then!

I tried typing "python" too and the Python prompt then appeared.  I typed some basic Python commands like "print 'hello world'" and it worked too!

I was thinking if there was a way to find out just like the Add/Remove Programs that I was used to when I was still using Windows XP/7 back then.

Cheers!
Apple Menu > About This Mac >

In the resulting window: (More Info)

In the side bar of the resulting window: Software > Applications

Columns presented:

Application Name | Version | Last Modified

Click on a row to see more details:


Kind (architecture)
64 Bit
App Store
Get Info String
Location (in the file system)


I see Python this way (3 different versions actually) but not PHP or Ruby.