Vikidia

Vikidia is an encyclopedia written for 8 to 13-year-old children and anyone seeking easy-to-read content on a subject. 

The content that is generally considered as inappropriate or that is generally considered as possibly offensive for this age range is excluded. 

Vikidia is free content that anyone can edit, use, and modify according to the principle of Free Knowledge. The general license used is CC-BY-SA.

Vikidia currently has more than 2,000 articles in English language.

https://en.vikidia.org/wiki/Main_Page

ChemWiki

The ChemWiki is a collaborative approach toward chemistry education based on an open access wiki environment to supplant conventional paper-based books and an effort to supply chemistry knowledge to the community. It's development is currently directed by UC Davis Professor Delmar Larsen.

The ChemWiki provides students and teachers with an explanation of the core, textmaps, wikitexts, homework, worksheets and visualizations. The materials covered include: organic, inorganic, physical, and analytic chemistry.

http://chemwiki.ucdavis.edu/

Simple English Wikipedia

When you learn a language reading can also be very helpful. You can learn vocabulary in context, texts that you read show you new expressions that you can use when you write, you can learn at your own speed, etc.

Sometimes the level is too high and you should read something simpler. Simple English Wikipedia is a subdomain of the regular Wikipedia It uses simple English words and shorter sentences. It is for everyone. That includes children and adults who are learning English.

You can find more than 115.000 articles on Simple English Wikipedia.

It seems like a great idea.

https://simple.wikipedia.org/wiki/Main_Page

#ELTchat

#ELTchat started in September 2010 when a group of ELT professionals began to use Twitter to discuss topics of their interest. It began with the aim of creating a freely available social network for ELT professionals offering mutual support and opportunities for Continuous Professional Development.

Now, every Wednesday at 12 pm (GMT) and 21.00 pm (GMT), ELT teachers from all over the world log into their Twitter account and for one hour hold an online discussion on a topic they have selected. The conversations can be followed by following the #ELTchat hashtag on Twitter.

Every Saturday, one of the moderators will put up a blog post on the #ELTchat Blog asking teachers who follow #ELTchat to propose some topics for the next chats. #ELTchat followers can go to that post and suggest topics in the comments under the blog post.

On Sunday evening, the moderators review the topics and create an online poll. #ELTchat followers are then invited to vote on the topics until Wednesday morning. Once the poll closes the top two topics become the subjects of the discussions.

After each chat, a transcript is posted on the #ELTchat wiki

Every month, a podcast, featuring an interview with one of their followers, interviews with well-known ELT authors and a quick summary of the past month's #ELTchats on the podcasts page.

(Source http://eltchat.org/)

Wikispaces on YouTube

Launched in March 2005, Wikispaces is Wikispaces is a hosting service based in San Francisco, California. The Wikispaces YouTube channel contains screencast videos created by Wikispaces to show you how to utilize some of their useful features.

http://www.youtube.com/wikispacesvideos