the computer bulletin'board
edited by
RUSSELLH. BAT Kenyon College Garnbier, OH 43022
NCSA Mosaic: An Internet and Hypermedia Browser Brian M. Tissue, Ching-Wan Yip, and Yue-Ling Wong Virginia Polytechnic Institute and State University Blacksburg, VA24061 NCSA Mosaic
NCSAMosaic is an internet information browser and World-Wide Web (WWW) client that is being developed by the NSF-funded National Center for Supercomputing Applications (NCSA) at the University of Illinois, Urbana-Champaign. Versions of NCSA Mosaic exist for UNM workstations, Microsoft Windows, and Macintosh, which are available at no charge via FTP (see the table). NCSA Mosaic is useful as a navigational tool to retrieve chemical information efficiently on the internet, and as a hypermedia browser to view materials that are written in a standard hypertext markup language (HTML).All of the HTML documents on internet servers around the world make up the WWW, which is a distributed hypermedia system that was started at CERN ( E u r o ~ e a nParticle I'hysics Lab,. The best sources 2 information ahout the WWW ~rniectand hv~ermediabrowsers are found in i&od;ctory do&nents on the web itself (several are listed in the table), and in a WWW-FAQ (frequently-asked questions) that is periodically posted to the alt.hypertext and comp.infosystems.wwwUIusersnewsgroups. The sites and documents on the WWW are identified by uniform resource locators (URLs). The URL's are essentially addresses that also specify the format of the information (see next Darama~h).The ability to link together different iocuments makes hyoertext effective for distributing information in hrtual libraries (electronic cataibgs that provide starting pointslpointers to the location of data and resources), and in training and education ( I , 2).A survey of chemistry department WWW serversfound departmental information, research databases and preprints, course information, multimedia demos, such a s graphics and movies of molecules and reactions, and hypermedia chemistry tutorials. The patterns of use on the Virginia Tech chemistry server range from accesses by users who are just "looking around" to users who take an in-depth look at the department information or the chemistry tutorials. The internet offers access to a large amount of chemical and chemical education information, ranging from chemistry databases, departmental information, educational programs, and multimedia The and programs are archived in many differentformats and require the appropriate retrieval tools to access. Obtaining information over the internet can be a frustrating
Department of Chemistry Organic Chemistry tutorials Laboratow Techniaues
V A 2406602f2, y,pm@vt edu
@computer Graphics
WI
A QulckTrme movie showing asp~rinin thin bond, ball and shck,liquorice, W W ,and raytxace representations.
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Journal of Chemical Education
An MPEG movie ofmtating DNA.
m ~ r m n i Chemisbv c Tutorla1 Dr Yue-Ling Wong. Chemldw Depertrnent. VPI&SU, Blschsburg, V A 24061-02f2,y p W t e d u
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Screen views oftwo HTMLdocuments using NCSAMosaic for Macintosh. Clicking on the highlighted Computer Graphics on the top screen with the finger pointer retrieves the bonom screen. The bottom screen has been artificiallylengthened to show the full document.
Selected WWW Resources process especially for students who are novice mmputer users. There are many different navigation tools and internet retrieval methods Obtaining NCSA Mosaic: anonymous Rp from Rp.ncsa.uiuc.edu such as e-mail listsen: FIT(Iile-transfer proto- WWW home page: col) and telnet, which recently were reviewed in this Jouml(3). NCSA Mosaic offersan inte- HTML specifications: grated tool that uses a consistent user interface that can access these services and WWW-hyper- WWW virtual library: media documents via H l T (hypertext-transport (list of WWW sites by protocol), WAIS information, gopher, Usenet subject) NhTPNews, and multimedia documents including MIME e-mails, images in GlF, JPEG, and List of intemet chemistry TIFF format, audio sound files, and video or ani- resources: mation in MPEG or QuickTime format. The Virginia Tech home page: NCSA Mosaic user sees a uniform interface for (with links to chemistry hythe different types of information even though Dermedia tutorials) they are stored in different formats. Clicking on ~ ~ r.o p r i aprote an item accesses it throueh the a .. defmes an inline image, ... define headers, places horizontal rules, and the
- ...
structure defines an unordered list. The ... are the anchors that define hyperlinks to other documents and highlight (underlined in the figure) the text between the bracket sets. The current HTML standard has some limitations for scientific writing such as the lack of math symbols and greek letters. A new version (HTML+) is under development that includes these capabilities and other advanced features. NCSA Mosaic is intended for browsing hypermedia documents hut it is not a full-function hypertext creation tool. Programs are available that serve as stand-alone hypertext editors, templates for popular word processors, and conversion programs, e.g., RTF to HTML, that help to create HTML documents. The best sources of information about the status of these programs are the akhypertext and comp.infosystems.www.users newsgoups and the "What's New" WWW page at NCSA. Literature Cited 1. Hadges. M. E.; Sasnen, R. M., Eds. M u l l i m d b Computing: CmseSfudiefrornMIT Pm>d Athano; Addison-Wesley Reading,MA, 1993: p 29. 2. &Van, Ba: Oliver, R.Undersfondin#Hyp~mnlin: Fmm Multimedia to WuolRe alily; Phsidan: Landon. 1993. 3. F S. J C ~ . ~ E iaw,70,20~~08. ~ ~ C .
Volume 72 Number 6 June 1995
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