Before XML became a standard and given all its shortcomings, what made XML so popular?

Question

Yes XML is human readable but so is comma delimited text and properties files.

XML is bloated, hard to parse, hard to modify in code, plus a ton of other problems that I

Answer 1

It's easier to write a parser for an XML dialect than for an arbitrary one because of tools that are available.

Using a DOM parser, for example, is much simpler than lexx and yacc, especially in Java where it was popularized.

Answer 2

Straight from the horse's mouth, the design goals of XML were:

1. XML shall be straightforwardly usable over the Internet.
2. XML shall support a wide variety of applications.
3. XML shall be compatible with SGML.
4. It shall be easy to write programs which process XML documents.
5. The number of optional features in XML is to be kept to the absolute minimum, ideally zero.
6. XML documents should be human-legible and reasonably clear.
7. The XML design should be prepared quickly.
8. The design of XML shall be formal and concise.
9. XML documents shall be easy to create.
10. Terseness in XML markup is of minimal importance.

The reason why it became popular was because people needed a standard for a cross-platform data exchange format. XML may be a bit bloated, but it is a very simple way to delimit text data and it was backwards compatible with the large body of existing SGML systems.

You really can't compare XML to CSV because CSV is an extremely limited way of representing data. CSV cannot handle anything outside of a basic row-column table and has no notion of hierarchy.

XML is not that hard to parse and once you write or find a decent XML utility it's not difficult to deal with in code either.

Answer 3

Some inherent qualities of XML that make it so popular and useful:

1. XML represents a tree, and tree-like structures are a very common pattern in programming. This is an evolutionary leap from record-based representations like CSV, made possible by today's cheap computing power and bandwidth.

2. XML strikes a good balance between human factors (it is plain text, and fairly legible) and computing practicalities (terseness, ease in parsing, expressiveness, extensibility, etc).

Answer 4

• You can be given an xml file and have a chance at understanding what the data means by reading it without needing a separate specification of your pre-xml data format.
• Tools can be used to work with xml generically. Where before, if everybody used different file formats: comma separated, binary, etc. You'd need to write a custom tool.
• You can extend it, by adding a new tag into the schema with a default value. And if done correctly, with xml that doesn't break all the old code that parses the xml but doesn't know about the tag. That usually isn't true with proprietry formats.
• Probably the main thing that makes it popular is it looks a bit like HTML, which lots of people understood previously. So it became popular, then because it was popular it became more popular because its nice to work with one standard that everybody knows.
• A bad thing is that xml is usually a lot bigger because of all the tags and because its text based than used to be used. But, as computers are bigger now, we can often handle that and its worth trading size for having better self-describing data.
• You can get off the shelf code/libraries that will parse/write xml.

Answer 5

It's cross platform. We use it to encode robot control program and data running in C under VxWorks for execution, but our off line programming is done under dot net. XML is easily parsed by both.

Answer 6

XML's popularity derives from other markup languages. HTML is the one people are most familiar with, but increasingly now we see "markdown" languages like that used by wikis and even the stackoverflow post form.

HTML did an interesting job, of formatting text, but it was insufficient. It grew. Folks wanted to add tags for everything. <BLINK> anyone? Layouts, styles, and even data.

XML is the extensible markup language (duh, right?), designed so that anyone could create their own tags, and so that your RECORD tag doesn't interfere with my RECORD tag, in case they have different meanings, and with sensitivity to the issues of encoding and tag-matching and escaping that HTML has.

At the start, it was popular with people who already knew HTML, and liked the familiar concept of using markup to organize their data.