I’m seeing a lot of camelCase word structures at the moment.
camelCase, also known as ‘medial capitals’ in the OED, is the practice of writing compound words or phrases in which the words are joined without spaces.
The practice is known by many other names, the most common of which is Pascal case for upper camel case.
In UpperCamelCase, each element’s initial letter is capitalized within the compound and the first letter either upper case – as in ‘BlackRock’, ‘MasterCard’ or ‘PowerPoint’, or left as lower camelCase – as in easyJet’ or ‘iPod’.
An early systematic use of medial capitals is the standard notation for chemical formulae, such as NaCl (Sodium Chloride), that has been widely used since the 19th century.
In the 1970s, medial capitals became an alternative (and often standard) identifier naming convention for several programming languages.
Computer programmers often need to write descriptive (hence multi-word) identifiers, like ‘end of file’ or ‘char table’, in order to improve the readability of their code.
It was only in the late 1960s that the widespread adoption of the ASCII character set made both lower case and the underscore character ‘_’ universally available. Some languages, notably C, promptly adopted underscores as word separators (‘end_of_file’) however, some languages and programmers chose to avoid underscores, among other reasons to prevent confusing them with whitespace, and adopted camel case instead (‘endOfFile’).
One theory for the origin of the camelCase convention holds that C programmers and hackers simply found it more convenient than the standard underscore-based style.
Another account claims that the camelCase style first became popular at Xerox PARC. The PARC Mesa Language Manual (1979) included a coding standard with specific rules for Upper- and lower camelCase that was strictly followed by the Mesa libraries and the Alto operating system.
Since the 1980s, it has become increasingly fashionable in marketing for names of technology products (BlackBerry, YouTube), merged companies (PricewaterhouseCoopers, ExxonMobile, GlaxoSmithkline) and for naming your avatar in online gaming (SpongeBobSquarePants anyone?). However, camelCase is rarely used in formal written English and most style guides recommend against its use.
