6/103.3.6.3 The HotJava Browser
A new competitor of NN and MSIE is the HotJava browser![[*]](/Teaching/theses/1997/_idbde_/rpersche/images/foot_motif.gif)
from Sun Microsystems Inc. Version 1.0 of
HotJava was released in March 1997. Instead of just supporting Java, like
NN and MSIE, the HotJava browser is written entirely in Java.
The main difference between HotJava and other browsers is that the HotJava browser is not a monolithic program, but a small program which dynamically downloads parts of itself, as they are needed, from the network. To display a specific content, the browser loads a content handler, a Java class which contains the needed algorithms to handle this content. The type of content is determined either by the MIME type found in the protocol header, or by the extension of the filename (e.g. picture.gif). Even protocols are handled dynamically. After browsing an arbitrary URL, which has the name of the protocol as a prefix (see Section 3.3.3), the needed protocol handler is fetched from the net.
This dynamic content and protocol handling make the HotJava browser highly extensible. If providers develop a new protocol or dataformat, they will just provide the appropriate protocol or content handler. For users it will make no difference whether they use an old or new protocol. Nevertheless, we have to take care that the number of different protocols does not growing too fast, and that new protocols will just be established when necessary.
The HotJava browser is platform independent and supports network security. Furthermore, it is highly
customisable because the user interface is written in HTML and contains
applets, and, thus, can easily be changed by the end-user or by the
Internet provider.