Is windows 98 open source?

Because Microsoft makes a living from selling copies of Windows. If we all could just download the source and compile it, Microsoft would lose all revenue from home users.

Open source means that no one company or individual have proprietary implementation on the license of the software. Depending on the site that you choose to download the software from it may be...

They are 2 different things, not compatible in nature. However, you can have a project to have iOS, Windows, Linux, etc all running under your new open source operating system, then the answer may be...

JPEG files can be viewed in Internet Explorer / Windows Explorer with no additional software.

Yes, see openoffice.org