This npm. Asking this question was a fun little journey.

Right on the npm website, the very first sentence starts with “npm”, and they do not capitalize it.

That’s a pretty good precedent for not capitalizing it. It certainly looks awkward though, which is why I asked the question to begin with. It doesn’t feel right to me to start a sentence that way, and I’m sure other some other people would look at it and see a mistake.

Their own documentation forbids capitalization as well:

Straight from Raquel Vélez, an employee:

#But!

We don’t have to.

If you’re following the Chicago Manual of Style, they would say:

This makes life difficult, however, for those of us who cannot bear to begin a sentence with a lowercase letter. CMOS forbids so doing (except for names like eBay)—we advise you to rewrite. Some publications simply ignore the preference.

Emphasis mine.

“Rewriting”, as in, find a way not to start the sentence with the preferred-lowercase initialism.

This advice holds true for other situations/companies as well:

avoid: He said that EBay is where he bought his IPod.
instead, use: He said that eBay is where he bought his iPod.

avoid: eBay is where he bought his iPod.
instead, use: He bought his iPod on eBay.

#Or just burn it all down