Arena: Frequently Answered Questions

Will W3C continue its Arena development in the future?

Other testbed environements are likely to take over Arena's role within W3C, and we do not foresee putting much development resources into Arena at this point. We are looking for pople that would be interested in taking over the Arena developments.

Arena style sheets do not seem to work as specified?.

Arena's support for style sheets has not been keeping up with the specification, and we encourage you to use some of the other clients that support CSS.

Why was Arena developed?

Arena's primary purpose was to be a testbed for new features of the web. In the past, we have implemented HTML3 features including tables and math, style sheets and new graphics formats such as PNG. Also, Arena has been a testing tool for the W3C Reference Library.

What is a style sheet?

HTML was not designed to give authors control over the final presentation of a document. Fonts, color and volume has been the domain of the reader/browser. Many authors want to influence the final presentation, and many readers would like them to. Style sheets provide a way to attache presentation hints to the documents without affecting HTML. This is a much debated issue, and you may want to read more of the background material available.

What is HTML3? HTML 3.2?

See the W3C resource page on Markup for more on this.

How do I specify colors in the style sheet mechanism?

You can either specify colors in hexadecimal RGB values (both 3 and 6 acharacter are accepted, e.g. #F0F, or #FF00FF), or using names that your window system (i.e. X11) knows.

Using the new style sheet mechanism I don't seem to be able to to control the colors accurately, why?

The style sheet mechanism does not allocate any new colors, but reuses the ones found in the dithering cube. Arena will give you the best approximation available.

How do the style sheets cascade?

The style sheet found in your initial document becomes your personal preferences. It will be applied to other pages, unless the other page has its own style sheet. If so, the two styles will be merged with preferences given to the latter document. Extra weights can be added with the "!important" construct. See the CSS specification for more on this.

Why isn't Arena available for my flavor of unix?

When releasing a new version of Arena, we compile for the platforms that are easily available (sunos, solaris, linux, sgi). Unfortunately, several popular platforms are not represented there. We therefore make source code available for porting, and can point to binaries that others have compiled.

How do I prevent Arena from going to www.w3.org each time it starts up?

Unless instructed otherwise, Arena will fetch the relevant release page from the www.w3.org server. It's a useful page (that you also can reach through the "Help" button), but you may not want to do this every time. Either, start arena with a URL as an argument (e.g. arena http://www.cern.ch/), or set the environment variable WWW_HOME to a URL (in csh: "setenv WWW_HOME http://www.cern.ch/").

How do I convert LaTeX maths and tables to HTML3?

Janne Saarela at CERN has written a translator to do this. It's name is math2html and it is freely distributable.
Other translator is written by Marcus Hennecke which only translates tables. It can be retrieved from If Arena finds HTML errors in the document, she flags it in the upper right corner. (The number in parenthesis is an internal error code, not line number or number of bugs.) In most cases, Arena and other browsers will still be able to show the docuement as intended by the author, but who wants to be seen in cyberspace with a bad HTML flag?

How can I see HTML errors?

If you want to see - and fix - the errors, press the "Edit" button. Arena will start the editor specified in the EDITOR environment variable (or using the "-editor <editor>" option). The raw HTML will be inserted in the buffer along with short error messages camouflaged as comments. You can set the maximum number of errors to be flagged using the -badflags option.

After have been through an edit cycle, you will also see the errors when toggleing the view button.

How can I edit HTML in Arena?

Start the editor as described above. Make your changes, save the buffer, exit the editor and Arena will show you the edited document. To save the file, either press the "SaveAs.." button and type in a file name (no expansions are supported yet), or go into your editor and save the buffer into the proper filename from there.

What are the command line options?

How do I run Arena from behind a firewall? Has it been SOCKSified?

Arena is not SOCKSified, but the CERN httpd proxy server is. Therefore, you can get through your firewall by pointing Arena to a proxy server running on the inside.

How does Arena cache documents?

Currently Arena doesn't cache in memory but uses disk for this. By default, Arena will write fetched documents into /tmp. E.g. http document from CERN's info server will go to /tmp/http/info.cern.ch/... When exiting, Arena will delete all cached documents and the corresponding directory structure. I.e., the disk cache is not persistant. Yet.

Also, if you run several Arena processes simultaneously on the same machine you may want to specify different cache directories as they will not be able to take advantage of each other's caches. See command line options.

What X11 resources can be set?

We are moving away from the platform-specific X11 resources to style sheets that can roam the web. For more on how to write a style sheet, see the draft specification. Note that the syntax has changed over time, so make sure you have the latest version of Arena. If you use an earlier version, see the style sheet examples under the help page.

What hotkeys does Arena support? Why not <space>?

Arrow keys will move you around in the current document. Ctrl + arow keys will take you page up/down and forward/backward in history. Also, the following X11 keys are supported: Page Up (XK_Prior), Page Down (XK_Next), Home (XK_Begin) and End (XK_Home). We have not been supporting some of the other common hotkeys (e.g. <space> for Page Down) because this may conflict with future HTML editing. Enough people have asked for this to make us reconsider.

Why doesn't index searching, hotlists - or other features - work?

Arena'a primary purpose is to be a testbed browser. These things have been done before, so they're not that exciting.

How can I specify external viewers?

Arena supports mailcap files. If you have a file called .mailcap in your home directory with this line in it:

image/gif; xv %s; quality = 0.95

Arena will display all images using the xv program instead of inline. The quality statement is an indicator of how well the application is able to display the data type. The HTTP server may use this information to determine what format to send to you. The default quality is 0.5.

Arena will also look for other mailcap files that the MAILCAPS environment variable points to.

Help! Arena displays all images externally. What's wrong?

You have probably declared an external viewer for GIF images. Arena does not distinguish between inline and "outline" images; if a viewer is defined, it will be used for all images.

How can I make Arena work with proxies?

Arena (i.e. the library) reads the http_proxy environment variable. Using csh, you could say

setenv http_proxy http://www4.cern.ch:8000/

This is also described in the CERN httpd documentation.

On my sun, Arena can't find any hosts. What's the problem?

Name resolving. Try using "the other" binary, e.g. arena-sun4-4.1.1-lresolv.bin or arena-sun4-4.1.1.bin.

Arena comes up in black and white (or grayscale) on my color screen. Help!

There is probably another application hogging the colors. Try quitting other applications (e.g. Netscape and Mosaic) and restart Arena. Or, you can start Arena with the "-cm" command line option (introduced in 0,98).

I submitted a bug report, but it still isn't fixed. Why?

We try to answer all reports and indicate a priority/complexity factor. We do not have the manpower to fix/implement all requests. But we hope you enjoy Arena anyway.