CamelCase is a convention and not a specification, so when there is a doubt it is common sense to stick to the language specification or implementation's naming convention.
The doubt I came across several times is acronyms. As this answer and this answer states it seems that Microsoft and .NET usually goes for camelCase for acronyms as in XmlDocument apart for 2 letters acronyms as in System.IO whereas Java prefers to always go for capitalized acronyms like SAXParser. Id, I think, is a different thing because it is an abbreviation of identifier rather than an acronym.
That being said, I would like to apply one of those conventions to JavaScript, so I started thinking that it would go towards the Java standard, but I found some weird things like window.XMLHttpRequest which mixes everything up.
Why is XML capitalized while HTTP is camelCased ? What is the common convention for JavaScript ?
