Curl has been part of the base install of Windows 10/11 since the December 2017 preview release. Bsdtar was added at the same time.

is it /real/ curl? Curl in cmd.exe is real curl, but in powershell that thing gets mapped to Invoke-Webrequest

curl in Windows Powershell is by default mapped to Invoke-Webrequest but it is not in powershell which you download or install via the store. I long ago removed the alias for curl in Windows Powershell too.

Tar, on Windows? What heresy is this. /s

winsock2 is basically the Berkeley socket API as well, so why wouldn't it be?

Having used both. It is close in that the api looks similar. But has a lot of interesting edge cases. Usually around error codes. One thing you learn quickly is win32 != bsd != linux. Each one has their own set of quirks and issues.