A website on the etymology of Chinese characters, with a lot of images of their past forms from different periods. Read more.

chineseetymology.org

Pinyinput is an input method editor (IME) for Windows that makes it easy to type Hanyu Pinyin with tone marks, like so: Hànyǔ Pīnyīn. Read more.

pinyinput.net

This is the best overview of spaced repetition research I have seen online or offline. It's thorough, well-argued and probably covers more than you were looking for. It's not specifically about Chi... Read more.

gwern.net

Douban is one of the most popular online Chinese communities and forums. You can read a wide variety of material - on almost any topic imaginable - from native speakers. It's a wonderful source... Read more.

douban.com

This is a neat little tool that converts pin1yin1 with numbers to pīnyīn with tone marks. Very simple, very useful. Read more.

lexilogos.com

Online Pinyin Input Method is a free online Chinese typing tool using Mandarin/Putonghua pinyin codes. We empower you to type Chinese online anytime, anywhere with any computer for free! Read more.

pinyinput.com

HiNative is a Q&A site where you can ask people all over the world about culture, language, anything. We support over 100 languages. Read more.

hinative.com

A Chinese discussion forum / social news site with discussions about almost everything. Good for reading about your particular interests or perhaps even participating in the discussions yourself. Read more.

bbs.hupu.com

Floomli is a free platform for exchange languages during video call, voice call or text conversation. By joining Floomli you become a part of a global language practicing network . The main goal of... Read more.

floomli.com

This is a review of Perry Link's book about Chinese. This passage sums it up pretty well, and although I haven't read the book (yet), it's high on my list of books to get my hands on: "In writin... Read more.

lareviewofbooks.org