Figure 4.6: NCSA Mosaic on an Apple Macintosh
Figure 4.7: NCSA Mosaic for MS Windows
Figure 4.8: EIT WinWeb for MS Windows
Figures 4.1 through to 4.11 show a range of WWW client programs. Although we can't possibly list all the available browsers here, the following are some of the most popular:
At the time of writing, Netscape is the most technically advanced of these clients, though no doubt the others will catch up fast. Most clients will download images one after another. Some (for example Mosaic for X) will wait until all the images have been downloaded before displaying the page. Others will display the text, and then as they complete each image load, they'll add it to the page being displayed. Netscape is even more fancy - it can download images from different servers simultaneously and display parts of images that have been received - so you get the best possible performance so long as you're not limited by your local network bandwidth, and get to see the data you've retrieved as soon as possible. Netscape also displays so called ``external'' images in its own main window - however this isn't always what's desired!
As HTML continues to evolve, some clients will implement new features before others. Not so long ago, active map handling and forms were new features only supported by a few clients - now they're pretty much standard. We'll no doubt continue to see new features for some time to come, but they should be implemented in such a way that old clients do not actually break, although they also will not do the right thing! If you're using one of the public domain clients such as NCSA Mosaic, all you need to do is retrieve the new version free of charge. See section for an idea of where the World Wide Web is going.