Terms of Use

Who this is between

This site is written and run by one independent developer in Hanoi, Vietnam, reachable at admin@tuanem.com. Everything below calls that developer me and calls you, the person reading, you.

There is nothing to sign up for and nothing to buy here, so these terms are shorter and less consequential than they would otherwise be. Most of what follows is about copyright and about the limits of what technical writing can promise.

Reading it costs nothing

Every page here is free to read, with no account, no paywall and no metered limit, and I intend to keep it that way. Advertising is what pays for the hosting, and it is described in the privacy policy. Nothing is hidden behind letting the ads load: reading with a blocker on is fine by me.

Free to read is not a promise that it stays online forever. I may edit an article, rewrite a chapter, or take a page down, without notice and without keeping an archive. If a piece here matters to you, save your own copy.

The writing is mine

The articles, the books, the site's design and the artwork are my copyright, and where a book's page names a co-author it is theirs too. Copyright exists by default, so this is not news — but it is worth saying what it does and does not stop.

Without asking me, you may:

• Read it, print it, and keep a copy for yourself
• Quote a passage — a paragraph or two — in your own writing, with my name and a link back to the page you took it from
• Link to any page here, from anywhere, including in a course or at work
• Use it to learn, and use what you learned in your own work, including work you are paid for. Ideas are not what copyright covers, and teaching them is the point of the site.
• Translate a passage for your own private use or study

Please ask me first before you:

• Republish a whole article or chapter anywhere else, in any language, even with credit and even for free
• Sell it, or put it behind a paywall or inside a paid course
• Publish a translation of a whole piece — I write in two languages myself and would rather do it or review it
• Turn it into a video, a book or a course of your own

The answer to a polite request is usually yes. Write to admin@tuanem.com and say what you want to use and where.

Two things get a firm no: passing my writing off as your own, and reposting it stripped of attribution onto a site that exists to farm search traffic. Feeding these pages to a scraper for either purpose is not made acceptable by the scraper.

The code samples are yours to use

The prose and the code are treated differently on purpose. Every code sample on this site — in an article, in a chapter, anywhere — is available to you under the MIT license. Copy it into anything, commercial or not, change it, ship it. No credit required and no permission needed.

A sample exists to make a point, which is not the same as being ready for production: error handling is often left out, names are chosen for the explanation, and the edge cases your program has are not the ones the example has. Read it before you ship it. Code I publish in a repository under my GitHub account carries whatever license that repository states, which is what governs it.

No warranty, and what that actually means

This site is technical writing by one developer, offered as-is. I try hard to be accurate — that is the whole appeal of writing about how things work underneath — but I do not warrant that anything here is correct, current or fit for what you are building.

Some specifics, because "no warranty" is vague and the real risks are not:

• It goes out of date. Swift, SwiftUI, Rust and the Apple SDKs change every year. A chapter accurate when written can be wrong two releases later, and a dated article is a snapshot rather than a maintained document.
• Performance claims are situational. Where I say one approach costs less than another, that is what I measured on my machine, on that version, in that benchmark. Measure your own case before you act on it.
• None of it is professional advice — not legal, not security, not financial. The privacy and licensing pages here describe my own practice; they are not a template for yours.
• You are responsible for what you ship. Test it, review it, and do not put a snippet from a blog into something that matters without understanding it.

To the extent the law where you live allows it, I am not liable for loss or damage arising from your use of this site or anything you took from it. Where your law does not allow a limit that broad, my liability is limited to the least the law permits. Nothing here limits liability for something that cannot be limited — fraud, or death or injury caused by negligence.

Advertising and links out

The ads on this site are chosen and served by Google, not by me. I do not review them and cannot vouch for what they advertise; an ad appearing here is not a recommendation, and a dispute with an advertiser is between you and them. If an ad here is genuinely offensive or looks fraudulent, tell me and I will block it.

The same goes for links in the writing: they point at other people's sites, which I do not control and am not responsible for. Where I recommend a tool or a book, it is because I use it — I do not take payment for a mention, and there are no affiliate links on this site. If that ever changes, the page carrying one will say so.

Using the site itself

It is a static site with nothing to abuse, so this list is short. Don't try to break into or disrupt the hosting, don't hammer it with automated traffic heavy enough to degrade it for anyone else, and don't mirror it wholesale. Polite crawling — a search engine, a feed reader, a personal archive — is welcome and always was.

Changes to these terms

When these terms change I update this page and the date below, and continuing to read the site afterwards is how you accept the new version. I do not keep a changelog of edits, so if the exact wording matters to you, keep a copy of the version you relied on.

Which law applies

These terms are governed by the law of Vietnam, where I live and where the site is run, and the courts of Hanoi are where a dispute would be heard. If you are a consumer somewhere whose law gives you rights that cannot be signed away, you keep them — this clause is not an attempt to take them from you.

If a clause here turns out to be unenforceable, the rest still stands. Write to admin@tuanem.com before anything reaches a court; in the entire history of this site, every problem has been a misunderstanding settled by email.