Interesting and practical collection of programming sites

Objective

This article is a collection of interesting and useful programming-related sites that I've collected from various parts of the Internet, listing the citations as much as possible (ongoing collection ...)

List

1. Hello World Encyclopedia

A collection of Hello World programs written in various languages

2.Font Awesome

Contains a large number of open source and free web icons

3.IT ebooks

It related ebook, available for download

4.OverApi

APIs related to various language technologies

5.DevDocs

Integrated online documentation

6. Free index of Chinese programming books

7.Oreilly Free ebook

8.CodeWars

Online Programming Brush Questions website

9.Regexper

Regular Expression Visualizer

Reference

https://zhuanlan.zhihu.com/p/23005451

Interesting and practical collection of programming sites