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with this approach. Firstly, not all users have the required expertise to <strong>in</strong>stall fonts properly onto their<br />

computers. Secondly, font files occupy considerable hard disk space. Thirdly, some client computers may be<br />

owned by an organization, and hence managed by dedicated personnel. End users may not have privileges to<br />

<strong>in</strong>stall font files onto these computers.<br />

Some of the exist<strong>in</strong>g WWW browsers, for example, the Netscape Navigator Version 2.0, are able to display a<br />

number of language encod<strong>in</strong>gs like Ch<strong>in</strong>ese (Big 5, GB), Japanese (EUC-JP, SJIS) and Korean (ISO-2022-KR,<br />

EUC-KR). However, there are two limitations for them.<br />

(1) They are not able to display mixed-language documents, that is, a s<strong>in</strong>gle document consists of more<br />

than one languages such as Ch<strong>in</strong>ese, Japanese and Korean will not be displayed properly. The<br />

selection of language encod<strong>in</strong>g is an explicit task to be done by end user.<br />

(2) If the client computer or the local font server does not have the font <strong>in</strong>stalled, the browser will not be<br />

able to display document us<strong>in</strong>g that particular character/font set.<br />

On-demand Font Service<br />

In order to solve the multi-l<strong>in</strong>gual document display problem, an on-demand font service that does not require<br />

system set-up and configuration is proposed. The on-demand font service should have the transmission speed<br />

no worse than the graphical method as stated <strong>in</strong> the Background section. The font service should be able to<br />

handle multiple font sets <strong>in</strong> different languages. In summary, the design goals of the proposed service are the<br />

follow<strong>in</strong>g:<br />

(1) Requires no privileged system set up<br />

(2) Capable to handle multiple languages<br />

(3) Acceptable speed <strong>in</strong> operation<br />

The first criterion is handled by us<strong>in</strong>g standard WWW browser support<strong>in</strong>g Java applets. There are a few Javacapable<br />

WWW browsers on the market. The merits of us<strong>in</strong>g Java applets will be discussed <strong>in</strong> [Merits of Us<strong>in</strong>g<br />

Java Applet].<br />

The second criterion is to allow multiple languages to be displayed. This goal is partly achieved through<br />

document syntax used on the server side, and another part is the Java applet developed to support different<br />

character and font sets with the same <strong>in</strong>ternal codes. That applet will also be able to display characters <strong>in</strong><br />

different font families, size, and attributes.<br />

The third criterion is handled partly by the 'on-demand' nature of the font service. Unlike the method to <strong>in</strong>stall<br />

foreign font files on client computers, which font image for all characters <strong>in</strong> a particular language is<br />

downloaded and <strong>in</strong>stalled, only the font images of the characters actually used <strong>in</strong> the WWW document are<br />

transmitted on the network. The improvement <strong>in</strong> speed, compare with the font file <strong>in</strong>stallation method, will be<br />

significant for lots of Asian languages, especially for Ch<strong>in</strong>ese, which are composed of tens of thousands of<br />

different characters.<br />

The speed is further improved as there are expected to have repeated characters <strong>in</strong> a document. In the<br />

proposed on-demand font service, for the same character, the font image will only be transmitted once, and all<br />

further occurrence of the same character will be displayed by us<strong>in</strong>g the font image already transmitted and<br />

cached <strong>in</strong>to client computer memory. This improves the speed on WWW browser compare with document <strong>in</strong><br />

graphical <strong>format</strong>.<br />

Merits of Us<strong>in</strong>g Java Applet<br />

Java [Hoff et al. 96] is an Object Oriented (OO) language developed by Sun Microsystems for distributed<br />

comput<strong>in</strong>g environment.

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