Microbrowser

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A microbrowser (sometimes minibrowser or mobile browser) is a web browser designed for use on a handheld device such as a PDA or mobile phone. Microbrowsers are optimised so as to display internet content most effectively for small screens on portable devices and have small file sizes to accommodate the low memory capacity and low-bandwidth of wireless handheld devices. Essentially, they are stripped-down web browsers.

Contents

Underlying technology

The microbrowser usually sets up the cellular networks themselves and gets content written in XHTML Mobile Profile (WAP 2.0), or WML (WAP 1.3 which was based on HDML). WML and HDML are stripped-down formats suitable for transmission across limited bandwidth, and wireless data connection called WAP. In Japan, DoCoMo defined the i-mode service based on i-mode HTML, which is an extension of Compact HTML (C-HTML), a simple subset of HTML.

WAP 2.0 specifies XHTML Mobile Profile plus WAP CSS, subsets of the W3C's standard XHTML and CSS with minor mobile extensions.

Newer microbrowsers are full-featured Web browsers capable of HTML, WML, i-mode HTML, cHTML, plus CSS, ECMAScript, and plug-ins such as Macromedia Flash.

Pioneers

The so-called microbrowser technologies such as WAP, NTTDocomo's i-mode platform and Openwave's HDML platform have fuelled the first wave of interest in wireless data services.

A British company, STNC Ltd., developed a microbrowser (HitchHiker) intended to present the entire device UI in 1997. The demonstration platform for this microbrowser (Webwalker) had 1 MIPS total processing power. This was a single core platform, running the GSM stack on the same processor as the application stack. In 1999 STNC was accquired by Microsoft and HitchHiker became Microsoft Mobile Explorer 2.0, not related to the primitive Microsoft Mobile Explorer 1.0. HitchHiker is believed to be the first microbrowser with a unified rendering model, handling HTML and WAP along with EcmaScript, WMLScript, POP3 and IMAP mail in a single client. Although it was not used, it was possible to combine HTML and WAP in the same pages although this would render the pages invalid for any other device. In addition, Amstrad's ill-fated e-m@iler and e-m@iler+ products used HitchHiker as their operating systems. Mobile Explorer 2.0 was available on the Benefon Q, Sony CMD-Z5, CMD-J5, CMD-MZ5, CMD-Z7, CMD-J7 and CMD-J70.

A freeware (although later shareware) browser for the PalmOS was Palmscape, written in 1998 by Kazuho Oku in Japan, who went on to found Ilinx. Still in limited use as late as 2003.

Released in 2001, Mobile Explorer 3.0 added iMode compatibility (cHTML) plus numerous proprietary schemes. By imaginatively combining these proprietary schemes with WAP protocols, MME3.0 implemented OTA database synchronisation, push email, push information clients (not unlike a 'Today Screen') and PIM functionality. The cancelled Sony Ericsson CMD-Z700 was to feature heavy integration with MME3.0. Mobile Explorer development had ceased by mid-2002.

Opera Software pioneered with its Small Screen Rendering technology. Opera Browser is able to relayout regular web pages for optimal fit on small screens and medium-sized (PDA) screens. It was also first wiedly available mobile browser to support AJAX.

Small-screen rendering limitations

As mentioned, not only do microbrowsers need to be small in file size, the display screen is also much smaller. Extreme care and meticulous detail must be considered in displaying HTML information onto such a small screen. Bandwidth is also extremely limited and so is the stability. Connections get cut off as with ordinary cell phones and PDAs that are wirelessly connected.

Popular microbrowsers

The following are some of the more popular microbrowsers. Some microbrowsers are really miniaturized Web browsers, so some microbrowser companies also provide browsers for the PC.

Default browsers used by major mobile phone and PDA vendors

User-installable microbrowsers

See also

External links

fr:Microbrowser ia:Microbrowser