Arena: Frequently Answered Questions

What's new in 0.95?
Inline support for JPEG images. Inline viewing of not-inlined images. Improved history mechanism. Numerous bug fixes. And some refreshingly new bugs.
Why another browser?
Arena's primary purpose is to be a testbed implementation of the evolving HTML3 specification.

Secondary, we want to make a good GUI browser based on the the CERN common code library. The library provides a common platform which will ensure future compatibility on the web. Also, if you are a browser vendor, it will save you time.

What is HTML3 ?
To learn more about HTML3 and how it may change the web, take the HTML3 guided tour. Also, a draft DTD is available. The DTD is normally a few steps ahead of the Arena implementation.
Why isn't Arena available for my flavor of unix?
When releasing a new version of Arena, we compile for the platforms available in the CERN park of reference machines (hp, sun, decstations (mips), sgi, ibm rs6000). Unfortunately, several popular platforms are not represented there. We therefore make source code available to volunteers for porting, but these platforms will necessarily be a bit behind. You can find binaries for several more plaforms in the subdirectories.
How do I prevent Arena from going to each time it starts up?
Unless instructed otherwise, Arena will fetch the relevant release page from the 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, or set the environment variable WWW_HOME to a URL (in csh: "setenv WWW_HOME").
What does the "Bad HTML" message in Arena mean?
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.

This works, but is fairly crude. We hope to move Arena toward GUI HTML3 editing, but this will require a couple of weekends.

What are the command line options?
How do I run Areana 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/ 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?
The following font resources have a meaning in Arena: h1font, h2font, h3font, h4font, labelfont, normalfont, italicfont, boldfont, bolditalicfont, fixedfont, ifixedfont, bfixedfont, bifixedfont, symbolfont, subsymbolfont, smallfont

Example: to change the font of the H1 element, edit your resource file (typically ~/.Xdefaults) to include a line like:

arena.h1font: -*-times-bold-r-normal--18-180-75-75-p-103-iso8859-1

In order for the change to take effect, you may need to reload the resource file (xrdb -load ~/.Xdefaults) and restart the browser.

What hotkeys does Arena support? Why not <space>?
Arrow Up/Down keys should work as expected. The same is true for for 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 forms, index searching, hotlists - or other features - work?
Arena'a primary purpose is to be a testbed to HTML3. In order to be so, some things need to work (among them forms), while others (e.g. hotlists) are irrelevant. Arena's secondary purpose is to be a good general purpose web browser. In order to succed, she needs several additional features (e.g. hotlists), but the manpower we can spend on this is limited. Among the things that can be expected are: forms, multithreading, hotlists, inline jpeg and style sheets.
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.

Help! Arena displays all images externally. What's wrong?
You are probably using an older version of Arena. Upgrade!
Will Arena source code be available?
We hope to make the source code available at some point. First, the code needs to stabilize a bit. Then we need to establish a way of dealing with incoming patches. We may even have to think about legal issues.
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=""

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.
I found a bug! How do I report it?
First, check to see if the bug has been reported. You can get to the bug list for the version that you are using by pressing "Help". You may also be told that you need to upgrade.

If you can't find it there, please mail a report to Please remember to state the version of: arena, your OS and your X11 display.

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 immediately. But we hope you enjoy Arena anyway.