Navegadores ligeros

http://unix.freshmeat.net/articles/view/695/
Amaya Descarga 10.0.1
http://www.fenrir.co.jp/en/sleipnir/global.html

1 comentario:

  1. _11 de agosto de 2008, 6:38

    Lightweight Web Browsers
    by Kamil Klimkiewicz, in Category Reviews - Sat, Jan 18th 2003 00:00 UTC

    The computers you meet on today's desktops are equipped with very fast processors (usually over 1GHz) and a few hundreds megs of RAM. Even very complicated and resource-consuming applications don't cause any problems for them. However, there are still old machines around which can't easily run such programs. They either don't launch them at all or run so slowly that sensible work can't be performed.

    Copyright notice: All reader-contributed material on freshmeat.net is the property and responsibility of its author; for reprint rights, please contact the author directly.

    Web browsers are certainly very complicated. They have to support many standards elaborated by the World Wide Web Consortium (HTML, HTTP, CSS, etc.), along with many other issues.

    On Linux, the browser which can do this almost completely is Mozilla. Unfortunately, as a very large and intricate application, it calls for a fast, modern computer. On the elderly ones, it runs very slowly. My PC has a 200MHz Pentium and 32 megs of RAM, and it takes about 10 seconds to launch Mozilla. To work with it is very inconvenient.

    The only solution is to use browsers which don't support all the Web standards, but are much faster and require less system resources. Such programs usually don't serve CSS, JavaScript, or more complicated HTML elements. Nevertheless, they render most pages correctly and can be successfully used in everyday work. Of course, you can't avoid situations in which you are forced to use Mozilla (or a similar browser).

    Weak computing power isn't the only factor in favor of lightweight browsers. Others include: individual preferences, the graphics environment being used (some of the mentioned browsers don't need X), and operating system configuration. Lightweight Web browsers are useful and important.

    In this review, I'll discuss four programs: Links, Dillo, Amaya, and w3m. In choosing applications, my primary requirements were: They had to be graphical Web browsers and they had to be Open Sourced. Of course, there are a few more that satisfy those requirements but were still omitted. Some of these are in a very early stage of development and aren't useful; others are too old and no longer supported.

    You might ask why the Phoenix browser isn't mentioned; after all, its developers call it lightweight. I don't agree with them. Phoenix is still several megs and takes more than five seconds to launch. In my opinion, it will never be fast and small enough because of its close connection with Mozilla.

    I hope this review is useful and will encourage you to try these interesting browsers. Feel free to write me about your feelings and observations.
    Links

    The Links project started in 1999. Its initial author was Mikulas Patocka. In 2000, more developers joined him: Petr Kulhavy, Karel Kulhavy, and Martin Pergel. All of them come from the Czech Republic and are students at Charles University in Prague. Besides the main programmers, more than sixty people from all over the world have contributed to the project. They provide translations, testing, bugfixes, graphics, etc. It is a quite mature Open Source project released under the GPL.

    In its beginning, Links wasn't supposed to support graphics at all. Mikulas Patocka wanted to make a Lynx-like browser with some additional features. It did its job well in those days, but then more people were invited to the project. The larger group of authors decided to fit the browser with support for graphics and JavaScript and many more features. Great progress has been made since then. Links runs on many platforms (Unixes, BeOS, OS/2, and Windows) and in many graphics modes (SVGAlib, X, the Linux framebuffer, and others). It is very fast and stable.

    It has served Web pages in graphics mode for two years, and is very good and mature at it. Its JavaScript support is quite unusual in this sort of browser. It isn't as functional and powerful as that in Mozilla or Internet Explorer (many elements of the language itself aren't supported, and the DOM implementation is rather poor), but for many sites, it is just enough. Such functions as opening new windows and rollover images (which, in fact, are the most often-used) work without any problems. Most importantly, almost every aspect of script functioning can be controlled by the user, so you don't have to put up with unnecessary and unwanted popup windows when you enter a site. You simply decide whether or not you want to have them opened.

    For displaying Web pages, it is the best-implemented of all the browsers covered. HTML 4.01 is almost fully supported, so it's no problem for Links to show inline frames (though in some less practical way) or complicated tables. Even the positioning of page elements is exceptionally good; everything is placed where it should be. On the downside, Links doesn't support CSS styles at all. Personally, I don't find this a big disadvantage, since most sites based on CSS look good anyway.

    Links uses its own set of fonts (because of portability issues), and thus doesn't depend on those delivered by the operating system. You could find this very useful, but, unfortunately, there is one big disadvantage to this implementation: There is no support for text selection. It isn't possible to copy some useful information or even paste the URL you want to visit (you must enter it manually or start a new Links instance). Another weakness of this solution is the lack of italic fonts (the bold style is used instead). (There is an unofficial branch of Links, links-hacked, which solves these problems as well as many others.)

    Links also supports HTTP 1.1 (though the HTTP Authentication mechanism doesn't work), HTTPS, FTP connections, background downloads, keepalive connections, and hierarchical bookmarks. On the downside, it doesn't support plugins, so Java applets and Flash pages won't work.
    Summary

    Advantages:

    * good HTML support
    * speed (it starts in less than 2 seconds)
    * a good user interface
    * portability
    * both text and graphics modes
    * quite good JavaScript support

    Disadvantages:

    * no support for CSS
    * no support for Java applets or Flash
    * no support for HTTP Authentication
    * no support for text selection

    Links is the browser I use for everyday work. I have to launch Mozilla for the most complicated sites (those which use DHTML or CSS heavily), but the others work very well and look very good in Links. The Czech browser is very mature, with a nice user interface and features which help to make your Web surfing pleasant.
    Dillo

    Dillo is in an early stage of development even though, according to the changelog, the project started in 1999. Its maintainer from the beginning has been Jorge Arellano Cid. Besides him, there are three core developers and three steady developers. Unfortunately, the authors can no longer contribute to the project as actively as before, and are looking for a sponsor or other funding method.

    The main factors being considered during Dillo development are speed and size. That's why the browser has been written entirely from scratch (only a few parts were taken from Gzilla). The whole is based on GTK+. Dillo is one of the fastest and smallest browsers (it competes even with text browsers in this field). The executable is less than 300kb and starts in less than 2 seconds.

    As for functionality, Dillo is a bit worse than Links, but, as I said, this results from its early version and not-so-active development. Fortunately, it can be successfully used in everyday work, and you won't need to launch a more feature-rich browser as often as with Links (or the other ones). Pages are rendered fairly well (and very quickly), though some HTML elements (such as frames) aren't supported. Quite rarely, a Web site is shown in a strange way. Some problems may occur when a page uses JavaScript, Java, or Flash (which aren't supported). Moreover, Dillo doesn't handle FTP or HTTPS connections. Like Links, it lacks text selection support; I hope this problem will be fixed soon, since it really makes surfing difficult.

    One of Dillo's advantages is the way it handles history issues. A few recently-viewed pages are stored in memory, so clicking the back or forward button produces an immediate effect. There are also other mechanisms that cause sites to load rapidly.
    Summary

    Advantages:

    * speed and size (really impressive!)
    * good page rendering
    * some nice configuration options
    * Dillo can be (and, in fact, is) used on mobile devices such as PDAs

    Disadvantages:

    * it lacks many features
    * it's in early stage of development
    * a few HTML elements aren't supported

    It's hard not to appreciate Dillo's speed, its basic and most important strength. The browser not only launches very quickly but also renders pages and loads them from cache almost immediately. Besides this, it manages to draw Web sites quite well and can be successfully used in everyday work.

    I believe that this small application will be widely used on embedded devices (it has been already ported to some). It fits them like no other browser. Maybe it's worthwhile to develop Dillo in this direction, then?
    Amaya

    Amaya is one of the most interesting applications covered in this short article. The project is managed by the World Wide Web Consortium (W3C), a quite solid institution. It is used as a testing ground for new Web technologies (it supports MathML, SVG, etc.). The first public version dates to 1996, and the current one is 7.1. It is developed very actively; new releases are published very often, sometimes more than once a month. Nevertheless, it is fairly stable.

    Since the W3C uses Amaya to showcase its new technologies, it supports many standards, even the newest ones. It gives you an opportunity to check them out and even (thanks to its editing capabilities) create something really interesting. Unfortunately, such an approach makes it very hard to cope with all the issues, so support for recent technologies, though initially implemented, isn't complete. Even the support for the elderly ones is sometimes not mature enough. It is worth the wait for the next release, however, since each usually adds support for a large number of features and fixes most bugs.

    Let's look at what is most interesting to us, the browsing capabilities of Amaya. I'll cover the other features later.

    Amaya supports such standards as HTML 4.01, XHTML, and CSS. The latter, however, isn't implemented well, since many elements aren't handled correctly or aren't handled at all. Fortunately, the situation is getting better with every new release. Also, HTML frames don't work (and probably never will; the Amaya authors find them incorrect and think they should be removed from the language itself).

    Web pages are rendered quite well, though problems may sometimes occur (e.g., text or images shown in the wrong place or one element covered by another). Of course, the CSS support is a big advantage, and the appearances of many sites better fit their authors' ideas than is the case with the other browsers. Another feature which distinguishes Amaya is that you can select and copy any piece of text (you can even paste it in the edit mode).

    There are a few issues with handling links in Amaya. For a start, you have to double-click to activate them, which can be quite annoying. Even worse, when you move your mouse over a link, nothing happens. The cursor doesn't change, and no information is shown in the status bar. It's often hard to figure out where the link leads.

    Besides the features mentioned above, there are also a few which are very unique and interesting. The zoom function is one of them. Imagine scaling an entire page, not only the text, but also the images, vector graphics, and other elements. Thanks to this, it is not a problem to make any document readable, even one with the strangest font settings. Of course, this feature is most useful for people with sight disabilities. The other property worth mentioning is the ability to show a page in many different views; you can see the structure, source, or table of contents. There is also a view that enables you to look at pages in a text-only mode.

    As for network protocols, Amaya does very well. HTTP 1.0 and 1.1 both work with no problems (thanks to the libwww library, also developed by the W3C). If you want, you can also use WebDAV or FTP to make a connection. This means that you are able to save the documents you edit directly on your server (the HTTP PUT method is available as well). For small Web sites, this is simply a great solution, since you need only one application to cope with HTML-related work.

    It's time now to show what makes Amaya a completely unique browser. As I said at the beginning, document types such as MathML and SVG are supported. Moreover, you can not only view, but also edit them. What about combining many technologies into one file? It's possible, so think about embedding equations in HTML and enriching the whole with nice SVG-based charts or drawings. And don't forget about XML and annotations! They are here as well.
    Summary

    Advantages:

    * it supports many document formats
    * it is not only a browser, but also a WYSIWYG editor
    * you can save Web pages directly to your server
    * it is being developed very actively

    Disadvantages:

    * many standards aren't implemented completely
    * some Web pages are displayed incorrectly
    * the user interface is sometimes annoying
    * frames aren't supported at all

    For those who like experimenting with new technologies, Amaya is just great. It is also suitable for preparing scientific works (and, of course, HTML Web pages). The HTML, SVG, and MathML mixing ability and the fact that Amaya is an authoring tool enable this. I guess that because of more work being done on these aspects of the application, browsing capabilities aren't as good as they could be. However, I think Amaya can be used in everyday work.

    Amaya is certainly one of the most interesting browsers mentioned in this article. The authors of the project are praiseworthy. However, I don't use Amaya very often.
    w3m

    w3m is quite an old browser (the first version was released in 1995), and it isn't being developed very actively. The author, Akinori Ito, doesn't add new features currently, he only tries to fix bugs. Besides the main branch, there are a few which equip w3m with features such as multilingual text support.

    w3m is really a text-based browser. The reason I decided to cover it here is that it now supports image displaying; you don't need to use external tools to view them anymore. You might think that it is little more than Lynx, but that's not true. It has many features that Lynx lacks, such as really nice support for table and frame rendering; even the most complicated are handled correctly. You can think of w3m as a real graphical Web browser.
    Summary

    Advantages:

    * speed and size
    * great for fast Web browsing or when you are looking for specific information

    Disadvantages:

    * lacks many basic features (forget about font styles or background images)
    * limited support for the mouse
    * a page has to be downloaded completely before it can be rendered
    * it isn't being actively developed

    Author's bio:

    Kamil Klimkiewicz switched to Linux a half a year ago. Before that, he used both Windows and Linux, but the latter was only his secondary operating system. He's now very happy and uses Microsoft's products very rarely. He really enjoys the freedom given him by the Linux and Open Source community. He is also interested in the history of computers and runs a Web site about it at http://historia.adrem.pl/.

    T-Shirts and Fame!

    We're eager to find people interested in writing articles on software-related topics. We're flexible on length, style, and topic, so long as you know what you're talking about and back up your opinions with facts. Anyone who writes an article gets a t-shirt from ThinkGeek in addition to 15 minutes of fame. If you think you'd like to try your hand at it, let jeff.covey@freshmeat.net know what you'd like to write about.

    http://unix.freshmeat.net/articles/view/695/

    ResponderEliminar

Suscribirse a: Enviar comentarios (Atom)