How do you write end user manuals?

As the title says.

Do you use Word, LaTeX or a different markup language?

Due to the nature of the document it should be

• easy to translate
• include in multiple formats (pdf, web)
• Change tracking

As a programmer with a science degree, LaTeX would be my go-to, no questions asked, way of doing this, however I realise that LaTeX has a bit of a learning curve.

So what do you use?