* Update free-podcasts-screencasts-en.md

added 2 new Podcasts.

* Remove trailing slash in URL

* This book doesn't seem to have anything to do with Mathematica.

* Added a free/open book on Algorithms in Python

Linked to the github repo, but it links to a PDF download from there.

* added author name

* implement #2357

* Jane Roe is an awesome writer

also, her website is secure!

* add two books in `-zh` list in `Python` section

* https -> http on explore-python link

* Added CodeIgniter Framework

* Added CodeIgniter Framework

* Update free-programming-books-ru.md

* the old site has not update so this is the new one

* remove trailing slash from url to satisfy travis

* Update free-programming-books.md

* Update free-programming-books.md

* Fix a broken link

* Fix broken link

* Adding new Python book

* Adding Python 3 Book

* correct markdown syntax

(I think we even have some free books *about* markdown!)

* Updated broken C# link 

The link for "Data Structures and Algorithms with Object-Oriented Design Patterns" under C# was broken. I updated it so it goes to the correct pdf file.

* change to Wayback link from discussion

https://web.archive.org/web/20161220072449/http://www.brpreiss.com/books/opus6/

Joy of Elixir is an in-progress book to teach newbies Elixir that I'm writing.

Thanks to @ckhrysze for the prompting to add the book to this list.

* Added Pyfiddle (https://pyfiddle.io/)

* satisfy Travis

* 添加正则表达教程

* Update free-programming-books-zh.md

* Python books: Formatting for multiple editions

* added ref to issue 2353

Add Free Competitive Programmers Handbook link to author's website. PDF available.

Include downloads link for a zipped html and pdf versions of a C book.

* Add Go playground

* Fix Travis build

* Remove broken link

* removed empty swift category

* Removed broken links

* Remove broken link

* removed empty swift category

* Python books: Formatting for multiple editions

* added ref to issue 2353

* .

* 1. Domain name http://reactjs.cn was sold and it is not related to react js for now. So I change it to another available site.

2. Tweak React to React.js

* fix ordering

* fix #2500

* removed empty android heading

Thanks for the contribution!
* add three book in free-programming-books-zh.md `Python` section

* order of adjustment

* remove the book in english and add author

* Add: The Official Raspberry Pi Project Book

* Add: The Official Raspberry Pi Project Book + Format

* Add LaTeX PDF

Add the "Breve Introduçao ao LaTeX2e" notes

* Add author name to "Breve Introdução ao LaTeX2e" notes

https://github.com/EbookFoundation/free-programming-books/issues/2500

Adding "Microsoft Technologies 3, including books on Windows Azure, SharePoint, Visual Studio Guide, Windows phone development, ASP.net, etc. collection by Eric Ligman"

* add PHP composer zh doc and laravel zh doc

add PHP composer zh doc and laravel zh doc

* add Vue.js zh doc

* add chinese PSR,Yii,Phalcon doc

PSR is PHP Standard Recommendations.Yii and Phalcon is PHP Framework.

* Sort by unicode

* Sort by unicode

```php
public function utf8_array_asort(&$array) {
        if (!isset($array) || !is_array($array)) {
            return false;
        }
        foreach ($array as $k => $v) {
            $array[$k] = iconv('UTF-8', 'GBK//IGNORE', $v);
        }
        asort($array);
        foreach ($array as $k => $v) {
            $array[$k] = iconv('GBK', 'UTF-8//IGNORE', $v);
        }

        return true;
    }
```

* sort by remark-lint-alphabetize-lists

* Fix travis-ci warning

www.jackkinsella.ie not available on https, flagged by link checker in issue #2500
Would appreciate double check.

* Added QB64 to the list

added QB64 to the list and a small course to help beginners get started

* Fixed for travis

* added author

* fixed name and title

* last commit

* oops

* I have a bad keyboard

* Update Competeivie Programming Link

* better url