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:
always npm, even if starting the sentence.
(this is a common question we get a lot :-) )
— Raquel Vélez (@rockbot) August 11, 2017
But!
We don’t have to.
Brand name capitalization is always at the discretion of the editor or style guide, so brands like WIRED or LEGO do not have to be capped
— Karen McGrane (@karenmcgrane) August 11, 2017
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.
Using npm …
The npm package manager …
Thanks to npm …
Anything to keep it capitalized as intended while not breaking basic capitalization 😅— Nicolás Bevacqua (@nzgb) August 11, 2017
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
this is why i don't capitalize ever
— jennmoneydollars (@jennschiffer) August 11, 2017
To be honest, I read the title as asking a completely different question.
Just the other day this topic came up and I described it thus:
“npm is a package management system developed by a frontend developer who had only heard about package management systems from someone who overhead them described in a pub once after half a bottle of tequila.”
To say the format hasn’t been thought out very well is an understatement. Huge file paths, ridiculous number of duplicate packages, and massive node_modules directories.
If you were really stuck needing to start a sentence with it and couldn’t stomach the lack of capitalization, I might put it in all caps, maybe using small caps, eg:
NPM is the node package manager and should never be capitalized.
That’s easy. Just spell it “Yarn” ;)
LOL!!! I love Yarn know that I have got the hang of it. Great time saver for regularly used libraries
Haha, I never even thought much about this before. If I hadn’t read this, I’d probably end up typing “Npm” to start a sentence. I couldn’t agree more though, it definitely feels weird to to not capitalize it.
With «sudo»?