I am a new one to the developer site would anyone like to tell me what does the term means open source platform. Because I have heard from someone that you can develop different Templates like Joomla Templates, CSS Templates and Magneto templates very easily on open source platform. I know one templates site as well http://www.templatemagician.com/
open source mean that you can develop the program like the program you want. as far as i know, the term source refer to the code that built the program. in the open source you can edit the source code and then makes it different program than the previous.
a platform can be;
1. hardware
2. operating system
3. development environment
open source hardware; all hardware details are open source, meaning, for example, a micro processor, if you have the design details open to public, anyone can manufacture that processor. because it is open source. source of a hardware is the design documents; it's schematic, it's pinouts, package type etc.
open source operating system: like linux. source code of the OS is open to public, so people can see it (which helps to write programs for it, especially system programs), modify it, use it as they want under a GPL or GPL like license. Linux is open source, Windows is not. you can not have the source code of Windows.
open source development environment: a programming, web developing, simply coding IDE which it's source code is open to public. there are many dev environments at SourceForge.net.
in general, for example people say; "my program is platform independent." meaning, it will work on any type of operating system. for example, a java applet will work on any browser, any OS; windows, linux, mac doesn't matter.