XML Article

Introduction

Extensible Markup Language (otherwise known as XML) is a markup language that defines a set of rules for encoding documents in a format that is both human-readable and machine-readable.

XML is usually used in web services and usually in conjunction with other web programming languages and technologies such as JavaScript and JSON. Over the years, many web applications have been developed, most of these applications can process XML data as it is a staple in APIs (Application Programming Interfaces), for example - Weather Widgets.

XML was developed by the W3C (World Wide Web Consortium) and was first published in 1996. The latest standard of XML is 1.1 which was released in 2006, XML does not get updated much as compared to other technologies.

Features

XML is excellent for handling data with a complex structure or atypical data.

Data described using markup language.

Text data description.

Human and computer friendly format.

Handles data in a tree structure having one and only one root element.

Excellent for long term data storage and data resuability.

Pros/Cons

XML has its pros and cons:

Pros	Cons
Usage - XML is heavily used for document storage and processing formats and it supports both online and offline data storage.	Limited hierarchical representation - There is a limited hierarchical model of representation compared to an object-oriented graph.
DTD and Schema validation - XML allows validation of data using DTD and Schema techniques to ensure the data is free from syntax errors. The schema enforces particular structure and form in the XML document.	Concrete and non-canonical - XML is very conrete and can introduce strong coupling between the actual representation and processing of the program.
Easy to maintain - It is easy to maintain the forward and backward compatibility despite change in the DTD (Document Type Definition) or the schema.	Demanding - XML is more demanding and precise compared to HTML. There are too many constraints making it difficult to construct a file.
Simplify data sharing - Due to its platform independent nature, XML can simplify data sharing between various systems. No need for conversion of data between different systems.	Data redundancy - Compared to other text-based data transmission formats like JSON, XML syntax is verbose and redundant.
Self-documenting formats - XML data formats describe its structure, field names, and the specific values for each data stored. It also represents the common data structures like lists, trees, and records.	No arrays - XML doesn't support arrays thus, you can't represent multiple data items of the same type using a single name.

Extra Programs

There are other technologies, languages, standards and frameworks that work with XML. These are:

Programming Languages - JS, C#, Java
Frameworks / Technologies - Node.js, Vue.js, ReachJS, Angular
Basic Web Technologies - HTML, CSS
Web Standards such as JSON.
Other - AJAX (Asynchronous JS and XML), Web APIs

Sources

Summary

In conclusion:

XML is described as one of the strongest and most versatile programming languages in the web-o-sphere (yes I just made that up). XML can be used in conjunction with many different programming languages can be used to manipulate and store data in an easy to read format. To make good web apps which use lots of data, you must be able to use XML or JSON, either of which are very good and easy to learn. XML can also be used to create new HTML tags to help structure data in a readable format, however XML is not as needed as it was 10 years ago.