Latex portability comes in multiple ways:
- An actual Latex file is merely a text file, which is just about the most portable format in computing.
- The Latex system that processes the text file and produces the finished document has been implemented on just about every mainstream platform you care to mention.
- The default output file format for Latex is DVI (which stands for device independent). This was around well before PDF was dreamed up and the high quality files can be viewed via software viewers or printed out. DVI is an open standard, so once again, readers are extremely portable and exist on most operating systems. Admittedly, DVI is hardly ubiquitous and nowadays it's often bypassed in favour for PDF (or it's very simple to convert to other formats like PS or HTML)
You can get Latex to do just about anything you can think of! Over the years, an overwhelming selection of packages to extend its potential and macros that can simplify complex tasks have come into being, most of which are freely available on CTAN. For example, Latex's main users are within academia and research institutions and they benefit hugely thanks to the Bibtex package that provides bibliography management - I pity my Word-using colleagues who suffer by actually manually word-processing their bibliographies (unless they've shelled out for a program like Endnote). There are other crazy packages that you can install which allow you to typeset music scores, chessboards and cross-words! CTAN is the main repository of these resources. Most are well documented and as you can imagine, with Latex being around for so long, the number of extensions is vast. The chances are, if you're struggling to do a task, someone will have undoubtedly written a package to solve it easily!Control
Even with simple documents, you can quickly become frustrated by Word's rather unintelligent interference. The hours that are wasted trying to position that image which you know will fit at the bottom of the page, but Word refuses to put it there! How many can relate to this experience? You have your 30 page document with text, tables and images. You just spent the evening getting it formatted nicely - all your figures in the right place and then you notice that one of your paragraphs isn't clear enough. You add one sentence, which then pushes an image on to the next page, leaving a massive gap at the bottom of that page where your image once was. This then daisy-chains down, knocking other tables and images out of place all the way to the end of your document! It's a real laugh. Fortunately, Latex is much more clever in this respect and positions your images and tables with a lot of common sense. So, if you want your image to appear at the bottom of a given page, it'll stay there!
Whilst Latex makes decent typesetting decisions for you, if you want to, you can have total control over the presentation of your document.Quality
It's difficult to disagree that the output from Latex is far superior to what Word can produce. This is emphasised greatest when it comes to documents with high mathematical content, which is a major strength for Latex. It also has much better kerning, hyphenation and justification algorithms that simply make the output far more professional than what any word processor. Its algorithms for laying out text are more sophisticated and extremely fine-grained. For example, the accuracy is so high because it uses a measurement known as a scaled point which translates as 100th of the wavelength of natural light!
Latex works with the concept of niceness (well, I suppose technically it's badness - which it works to minimise). Latex has a large set of metrics that it evaluates against when generating your document. It experiments with various permutations of parameters and determines the one which gives the "nicest" output. It can take the time to do this because it isn't interactive. Word processors don't have the computational resources available (yet) to carry out the equivalent calculations and still remain interactive. Also, many people forget that typesetting is actually a professional skill - people train for years to learn how to layout publications. Yet, as soon as you open a word processor, you go about committing typesetting sins all the way. Typesetters know for example that its easier to read sentences that are approximately 66 characters wide. Have a look in your books and count the letters! Also, why do newspapers and magazines have narrow columns? But, the default layout of a word processor gives an average of 100 words per line. I suppose many people don't mind, but you would notice if you read a lot of large documents.
A quick example. I took a document that I had used previously to demonstrate document structure in Latex. I used the same text and loaded it into Word and applied the equivalent styles. I've used default settings throughout. Word didn't have a style for abstracts, so I put the title in bold. View the Latex output to the Word output. The styles that Word uses aren't great. You could manipulate the default styles in Word to make it look more reasonable, but I've never been bothered because even if I could get it to match Latex stylistically, I still have to use Word, which I'd rather avoid!
Latex has been used regularly typeset entire books. Word processors simply aren't good enough for that job - they are used by the authors to write the content and these files are then imported into professional typesetting software. Ok, that's not strictly true - you could typeset a book in Word, just like you could drive a car with your feet - it's not a good idea though!Output
As mentioned, the default output is a DVI file. DVI was a clever little standard but unfortunately didn't take-off. It takes little effort to convert your document into a Postscript or PDF file (in fact, you can just use the 'pdflatex' command instead of normal 'latex' if you only ever want to create PDFs). There's no need to buy additional software such as Adobe Acrobat like you need to do to convert a Word document into PDF. (At least OpenOffice has its 'Export to PDF' functionality!)