AZair.com (AZair.eu) allow you to combine flights from multiple airports. Covers Europe, Mediterranean and Asia. Suggested in the previous "Ask HN: How do you find airline tickets?" [2]
Also, if you search for "A re-introduction to JavaScript" in HN Search, you will find previous posts of the same article with comments pointing to other similar sources.
I would like to suggest Nikolai Glinka's "Problems in General Chemistry," of which I have the original Russian edition but I see that it's been translated in English (https://www.amazon.com/Problems-General-Chemistry-Nikolai-Gl...). Reasons for my recommendation is that first, it's interesting, and second, every time I have used this book, all chemistry concepts made sense, unlike in the manuals we had to use in school. To rephrase MiB, this would be the final chemistry book I ever read if I decided not to pursue my studies in the subject further.
Also, I did not know much about the Glinka himself, but from what I've found from a quick web search was quite interesting: a representative of an ancient noble family, honored scientist, largest teacher-methodist, whose books for decades, determined the level of chemical education in non-chemical and chemical technical institutes of the USSR...
I don't know if the Publisher would believe as if they don't see that the ideas are the same that they have to send the proof to the people I am complaining about. I don't know if the court will believe, as they are not domain specialists and will judge by the letter of the law.
Not exactly a horror story, but here it one. I decided to send proofs to a well-known academic publisher in order to report colleagues who had used findings from my lesser-known research papers (published in lower-profile journals) and my PhD thesis as their key conclusions. The Publisher started an investigation, but I was told that my colleagues would need to see the evidence first. The Publisher would not disclose my identity, I was certain that my "colleagues" would have figured it out. So, I made the decision to call them first and ask for clarification. They requested me to send them their text and works for which I was claiming authorship while acting as though they had no idea what I was talking about. After I sent the email, they called back, berated me, and threatened me with a lawsuit for defamation for using the words "Below is the text from the paper, which contains ideas taken from my publications.". They explicitly used the words "by all possible means". Then asked for apology. I did apologize and urge the Publisher to halt the investigation, but was this the proper course of action? Back then I was scared, but I am angry now. My sin is that my papers and Ph.D. results are not published in the big academic publishing companies (so they cannot find the plagiarism), except for one in Elsevier.
Perfect data visualization of the current environmental and climate challenges that is open to anyone. The current environmental issues we face are portrayed with "Data layers" and discussed with "Stories" beneath. Stories like this should reach mass media to raise public awareness. Before we can focus on the (final) outer space (frontier), we must first fix our inner (terrestrial) space (ship) with a priority. Or not?
Yes, I can see that it's realistic and fun by reading some of the user reviews, like this one:
> Wow, this was so much fun! I work as a DevOps engineer, studied computer science, and have 20 years of work experience. This game creates several virtual machines when starting, with real operating system on them, real web servers, databases, web applications, and shows you multiple ways of hacking around networks, linux, web, php, passwords, authentication, privilege escalation, SQL injection, and MySQL in general. Everything I did in this game came up during my career in work in some form, and I had to protect systems against attacks like this too.
...there were a few things I learned, for example `sudo -l`, I'm going to use that all the time from now on.
I've already mentioned it in another comment, but (being unable to edit my question already) this is what I was thinking when I asked the question: an addictive game with progressive complexity and (possibly) time-limited challenges that make you feel like you didn't waste (hours of) time because of the knowledge (skills) you've gained.
I guess, I have to try some of the games that everyone has mentioned.
It seems that it counts by reading the description: "small programming puzzles for a variety of skill sets and skill levels that can be solved in any programming language you like. People use them as a speed contest, interview prep, company training, university coursework, practice problems, or to challenge each other." But since I haven't used it, you or someone else can have the final say. I was thinking of an addictive game with progressive complexity and time-limited challenges that make you feel like you didn't waste time because of the knowledge you've gained.
I'm not a security expert, but possibly being able to change my username in addition to changing my password due to safety concerns gives an extra layer of security.
[1] https://www.azair.eu/index.php
[2] https://news.ycombinator.com/item?id=36793357