infogr.am — Online charts & infographics.
Busuu — Practice your listening, reading, speaking and writing skills and interact with international community of native speakers.
Duolingo — Learn languages with a focus on gamification on mobile learning.
Lingvist — Learn a language in 200 hours.
LiveMocha — Activities, self-paced lessons, live instructor-led classes, and writing and speaking exercises in 38 languages. Learners can get personal feedback on grammar and writing for free.
Pimsleur Language Learning — Learn many rare languages this way of learning — Spanish, Portuguese, Chinese, and Greek.
Refugee Phrasebook — Open phrasebook for refugees and people who just arrived. Wonderful project that covers everything from data collection to organization to printing.
Webonary — Online dictionary of rare languages.
BBC Languages — Courses and other resources for people learning French, German, Italian, and others.
Endangered Language Resources — Resources for conservation, development, and documentation of endangered, minority, and low or under-resourced human languages. Links to many open source projects, all language related.
Google Translate — Translate 90 languages, use your camera to translate text instantly in 26 languages, and with two-way automatic speech translation in 40 languages. Also with offline iOS and Android apps.