Learn French: On parle anglais dans l'entreprise. - We speak English in the company.

Yes, on traditionally means "one" or "people in general". However, in modern, everyday spoken French, on is almost always used instead of nous to mean "we".

Why does the verb end in -e (parle) instead of -ons if the subject means "we"?

Even when on translates to "we", it is grammatically a singular pronoun—just like il (he) or elle (she). Because parler is a regular -er verb, you drop the -er and add the singular ending -e, giving you on parle. You would only use the -ons ending if your subject was actually the word nous (nous parlons).

Why isn't anglais written with a capital A?

In French, the names of languages are never capitalized unless they are the very first word of a sentence.

Why isn't there a word for "the" before anglais?

While French normally uses definite articles (like le or la) before languages, they are usually dropped directly after the verb parler (to speak).