Text editors you use daily may have trouble to open big XML files that are over 100 MB. Use the tricks and applications in this page to sort this problem out.
Trick 1: Use the browser!
If you just want to have a quick view at XML file, simply drag and drop it into your web browser. Tested with Chrome.
Trick 2: Change the file extension
Change file extension as txt. Then try to open it with your favorite text editor such as Notepad++, UltraEdit or Windows Notepad! They will open it if the size is below their limits. Thanks LosTechies for the trick.
Application 1: firstobject XML Editor
If you need more than viewing and highlighting, try this simple but useful application: firstobject XML Editor. It has tree view and a couple of other cool features.
Application 2: 010 Editor
Another simple XML editor. Details are here. More is discussed on Stack Overflow.
You may ask why not using professional XML editors such as Altova XMLSpy, XML Notepad etc. They have lots of advanced features. Therefore they spend more time to analyze the file. However, the applications above load the file into memory and show it in very short time.