1. Windows 7
1.1. pros
1.1.1. Applications & driver support – Undoubtedly Windows has the most number of applications
1.1.2. Easy to use – I think, this is because most computer users started their computing with Windows and are familiar with it.
1.2. cons
1.2.1. Not very stable – Windows is synonymous with the infamous "Blue screen of death" (BSOD). But Windows XP has changed this to an extend as it was reported as the most stable OS by Microsoft.
1.2.2. Because of the high usage, most spywares and viruses are targeted to this platform.
2. Ubuntu
2.1. pros
2.1.1. Free software – No cost, no restrictions – complete freedom.
2.1.2. Easily updatable on a good broadband internet connection – To install a new application, all you need is to search for the application in the distro’s package manager and install it. All dependencies will be taken care of automatically.
2.2. cons
2.2.1. Updating / Installing additional package can be difficult if you do not have an internet connection. While it is extremely easy to update/install packages if you’ve an internet connection, it may be very difficult if you don’t have one because of the possible package dependency issue. So you need to manually install all dependency packages before installing your desired package.
2.2.2. May be difficult to decide which Linux flavor. The options are plenty and a ‘non techie’ user may be confused to choose the right distro. But Linux has an excellent community and just ask your questions in the forums or user groups. You can always find a linux distro for almost all of your need.
3. Operation System definition
3.1. An operating system (OS) is an interface between hardware and user which is responsible for the management and coordination of activities and the sharing of the resources of the computer that acts as a host for computing applications run on the machine. ...
4. Chromium
4.1. Chromium is the open source web browser on which Google Chrome is based. The Google-authored portion of it is released under the BSD license, with ...
5. Mac OS X
5.1. pros
5.1.1. Applications – A large number of excellent professional applications are available in this platform and hence preferred by designers and other professionals.
5.1.2. Targeted less by viruses & spywares
5.2. cons
5.2.1. Cost of ownership is high – User is not free to try it out by paying for the operating system alone, instead the user is forced to buy new hardware at premium prices.
5.2.2. The Operating system is limited to a specific platform