To get crazy fast in the command line, try Command Line Challenge, practicelinux.com, learnshell.org and commandlinefu.com. Source: 8 months ago

I put something together very similar to this, https://cmdchallenge.com that I like a bit better because it has console input. There is also a Christmas edition "12 days of shell" https://12days.cmdchallenge.com that is more like a learning progression. - Source: Hacker News / 8 months ago

Nice to see this posted on HN! A while back ago I used them for the design of a site a built https://cmdchallenge.com/ which gives it a nice feel of achievement badges without using standard unicode characters that may look different depending on the client. - Source: Hacker News / 9 months ago

Cmd challenge is a website that gives you a linux terminal, and asks you to perform different tasks on it, so you sharpen your linux terminal skills. - Source: dev.to / over 1 year ago

Aye that's a good one. CmdChallenge is also quite nice. Source: almost 2 years ago

Use azirevpn.com/ they have port forwarding, wireguard, anonymous payments with crypto including Monero (very key) and other advanced privacy mechanisms implemented that make them unique. Probably closest competitor to Mullvad, quite cheap. 60 bucks for 1 year right now. Source: 12 months ago