Here is a list of various website of value in no particular order:
The Fire Kasina is a website about this powerful ancient kasina practice, with many audio reports, bits of advice on technique, and a free book, The Fire Kasina.
The Alliance for Buddhist Ethics "exists to affirm the importance of ethics in all Buddhist traditions so that the Buddhadharma can flourish with integrity for a future of equality and respect for all."
IntegratedDaniel - The creator of this site's homepage. His book, Mastering the Core Teachings of the Buddha, can be found there as well as an assortment of other useful articles. Those seeking to understand a lot of the model terminology used on this site should probably check it out. It also contains a lot of good advice on such topics as the Dark Night, realistic models of enlightenment, helpful instructions for practice, and other practical topics.
Kenneth Folk's dharma site, often referred to as KFD, is an early spinoff and current sister site of the DhO and contains a lot of crossover membership. However, a new public version is now back up and running and found here.
The Dharma Underground spawned the Dharma Overground, which spawned KFD and OE when the first Great Schism occurred, and then KFD had its own series of schisms, one of which spawned The Dharma Forum Refugees Camp, whose members include some of the early DhO members, and that spawned the grand attempt at re-integrating some of the fractured communities called awakenetwork.org.
Open Dharma Foundation works to create scholarships to support pragmatic practice, previously called the Pragmatic Dharma Foundation.
RetreatBase is a searchable database of places to go on retreat.
BodhiMonastery is a free online resource containing free online courses about the dharma.
DialecticalAmy is the blog and website of Amy Donohue on practice and this post-post-modern life.
The Hamilton Project is another site dedicated to practical dharma that spun off of the DhO and KFD.
Deconstructing Yourself is the site of Michael Taft and Jessica Graham and is dedicated to awakening and wisdom.
Deep Mindfulness Collective is the mentoring project of Rakhel and Janusz and is strongly influenced by Shinzen Young and other teachers.
Eric Gatley blogs about and teaches pragmatic meditation.
Anna Lutkajtis is a practitioner/researcher/scholar with an interest in the Dark Night who has published some great articles.
Acacemia.edu has a wealth of articles, books, and publications related to meditation and science, but not all are purely scientific, and there is plenty there for the general consciousness adventurer.
Inward Bound Mindfulness Education (iBme) helps train teens in mindful living and runs retreats for teens. Some great people work there.
There is a Reddit group dedicated to pragmatic dharma and high-level discussions.
Direct Pointing can be found at Liberation Unleashed.
Shinzen Young is a meditation teacher who was a friend of Bill Hamilton and teaches a modernized version of vipassana mixed with influences of Zen and Vajrayana. Har-Prakash Khalsa does videos of Shinzen and also teaches meditation and does his own videos and art.
Abhidhamma.Org "Books and articles about Theravada Buddhism. The theory and practice of satipatthana vipassana (insight meditation) according to the Pali Tipitaka."
Wisdom Library has a large collection of online text and dictionary resources.
Sutta Central is trying to put the whole of the Pali Canon online in English Translation for free, and they already have some large parts of it available. Highly recommended. Works best with Chrome Browser.
DharmaTreasure is the website of Upasaka Culadasa (aka Dr. John Yates), a Tibetan and Theravadan teacher who is interested in a modern, scientific take on ancient wisdom.
The Integral Dharma Institute is the dharma resource site run by Andrew Olendzki, an accomplished scholar of the dharma.
Dharmachanics describes itself as "A growing, peer-led, experimental, global online sangha. We provide support to members practicing meditation and mindfulness to be awake in the world, the world awake in us. We are an inclusive sangha that welcomes all traditions and schools of Buddhist practice and study. This is supported through live hangouts, an extensive video library, on-line forums, silent sitting sessions, book discussions and on-line retreats with leading Buddhist teachers. All members are welcome to participate and encouraged to suggest and create more content and discussions."
DharmaFarers has a lot of textual resources and things in translation.
http://hokai.info/ is the website of Hokai Sobol, a very skilled Vajrayana practitioner and scholar that was part of the core group that began at the DhO.
10% Happier is the journalistic meditation promotion project of the ever-personable and inquisitive Dan Harris of ABC News.
Post-Traditional Buddhism is a thoughtful, intelligent blog dediated to rational critique of current emerging Buddhism. It is also living proof that non-toxic things can actually arise from the speculative non-buddhist movement despite themselves, and is the home of the Imperfect Buddhist Podcast.
Kamalashila teaches meditation in the London area with Triratna.
Andrew Olendzki is a Buddhist practitioner-scholar who has been kind enough to post some of his helpful maps, tables and the like on his website.
http://www.constancecasey.com is Constance Casey's site.
robertthanattarigpa.blogspot.com/ is the blog of Robert Thomas Hindmarch.
www.vincenthorn.com/ is a link to the blog of an ex-DhO member and yet one of the core founders, Vince Horn. His current meditation teaching project with his co-teacher and partner Emily Horn is Meditate.io which is home to Mindfulness++, a revamping of meditation for the digital age. Buddhist Geeks has been resurrected, and there you will find hundreds of podcasts about meditation.
Leigh Brasington's Jhanas Page - A great collection of articles and information on the jhanas, created and assembled by jhana teacher Leigh Brasington.
Cyborg Buddha Project - The Cyborg Buddha Project was founded to "promote discussion of the impact that neuroscience and emerging neurotechnologies will have on happiness, spirituality, cognitive liberty, moral behavior and the exploration of meditational and ecstatic states of mind."
Spirituality Explained is the work of Frank Heine and an attempt to integrate neurobiology and meditative perceptual models.
Bhikkhu's Blog - A Canadian born Theravada monk ordained in Thailand in 1992. Abbot of the Arrow River Forest Hermitage.
Access to Insight: Readings in Theravada Buddhism - translated scriptures from the Pali Cannon and links for Theravada practitioners
Tai Chi Methods is self-explanatory.
Zen stories is self-explanatory.
Spiritual Experiences is a website where people post descriptions of spiritual experiences. It is a fascinating read.
The Dao Bums- Website about Taoism but links to other great meditation information. Lots of very bright people from different backgrounds, countries, knowledge bases.
Vipassana Fellowship - has great resources, including (at a glance) much of the Pali canon in HTML and Mindfulness in Plain English (Complete text in HTML)
Meditating In Safety - A site about the difficult experiences that can happen in meditation with a few examples and journal references.
BuddhaNet's eBook Library - contains many great books for download, such as Mahasi Sayadaw's Practical Insight Meditation and Thanissaro's Wings To Awakening (far too many titles to list here)
Buddhist Publication Society - Offers many great books by both western and eastern masters of the practice. Also has past newsletters available for download.
DhammaTalks.Org From their website, "This site offers an extensive collection of English translations of suttas from the Pāli Canon, as well as a multitude of free downloads of Dhamma from the Kammaṭṭhāna (or Thai Forest) Tradition of Buddhism. Ṭhānissaro Bhikkhu of Metta Forest Monastery is the speaker, author or translator unless otherwise noted."
Practical Insight Meditation - may be found here, and for those who want print versions of this and many other related books: http://www.bps.lk/meditation.asp
In This Very Life - (Online version) by Sayadaw U Pandita, also On The Path to Freedom (.pdf version)
Forgotten Books has a nice section of old and unusual Buddhist books online for free.
Pali Text Society publishes the only nearly complete printed translation of the Pali Canon in English, though the translation could use a bit of an update.
The Berzin Archives is a truly remarkable site about the Mahayana and Vajrayana traditions: top notch.
Pan-Buddhist Library is a broad resource for the various Buddhist traditions.
Shambhala Sun is now Lion's Roar and is a periodical about Buddhism.
Tricycle is a classic magazine about Buddhism.
Yoga Sutras Patanjali - An ocean of commentary and articles on the yoga sutras (and some other topics)
Buddha Net - Great eBook collection
A good article about the dark side of Gurus.
The Bodhisattva Ideal in the Theravada: an eye-opening article for those who think that the bodhisattva ideal is purely a Mahayana doctrine.
David Treleaven wrote Trauma-Sensitive Mindfulness, a valuable resource for those dealing with trauma who wish to practice meditation.
Buddhist Geeks - A free Buddhist podcast with interviews and dialogues with various western Buddhist teachers, scholars, and practitioners. Created and hosted by members of the Dharma Overground, as well as having several interviews with other members (including Daniel Ingram & Hokai Sobol) this podcast has a variety of good audio content on various topics and at different levels of depth.
Audio Dharma - "This site is an archive of Dharma talks given by Gil Fronsdal and various guest speakers at the Insight Meditation Center since 2000. Each talk illuminates aspects of the Buddha's teachings. The purpose is the same that the Buddha had for his teachings, to guide us toward the end of suffering and the attainment of freedom."
Ajahn Sumedho's dharma talks archive.
Birken Forest Monastery Dharma Talk Archives - this page has english talks from Ajahn's (mostly from Ajahn Chah's lineage; Thai Forest) from around the world
Collision with the Infinite - A great book review of Suzanne Segal's book. "As she stepped into a bus on a street in Paris, an unexpected mental cataclysm split her consciousness in two. A few months later, her sense of personal self disappeared forever."
DIY Dharma - exhaustive amount of audio, but poorly coded page taking a long time to load
Dharma Seed - has a truly massive compendium of free dharma talks (mp3 or streaming) by pretty much all of the mainstream Western Insight teachers, originally started by the remarkable Bill Hamilton.
Suan Mokh (Ven. Ajahn Buddhadasa)
NM Center for Meditative Inquiry and Retreat - Operated by Jay Cutts, this Center in northern New Mexico is for people from any meditation traditions (Tibetan, Zen, Vipassana, Hindu, Western) or no tradition at all, as well as for people interested in teachers such as Pema Chodron, Toni Packer, Thich Nhat Hanh, and Krishnamurti. Jay studied with Toni Packer for many years. Explore more deeply what meditative work is and how it sheds light on the concerns of our lives, not theoretically, but from a quiet listening that includes others and oneself.
Ven Ajahn Maha Boowa
Ven. Nanavira Thera Dhamma Page
Franklin Merrell-Wolff (here and here) - The writings of the American spiritual philosopher and Realizer, Franklin Merrell-Wolff (1887-1985), are deep, difficult and profound. His 3 books are classics among those with the insight to grasp their meaning. FMW was trained in mathematics, philosophy and psychology at Harvard. He abandoned a promising academic career and devoted 20 years to the pursuit of Enlightenment before realizing success. Because FMW is so difficult, not many people read him. Because his Realization is true, and he expressed it in precise, logical Western terms, many people should.
Puppetji - Puppetji is a guru/muppet who speaks his "wizdumb" on Youtube. Useful for periodic reminders not to take oneself so seriously.
Tutteji is one of the most hilarious, cynical and scathing critiques of the world of meditation.
ConsciousCults.Com provides many resources to "fill your hole".