The most demanded VK API documentation sections are collected at this page.

In this manual we described all supported types of authorization based on OAuth 2.0 protocol.
Description of standard scheme for requests forming which is used for the most of methods calling.
Detailed information about photo, audio, video and documents uploading to VK servers via API.
Review all ways of sharing content at VK.

Documentation about using API for community messages.
Documentation about creating community apps.
Manual for using payments in vk.com applications.
Documentation about using API for market in communities.
Library for working with VK API on external sites.
Descriptions of methods for interaction with VK interface in Flash and iFrame applications.
Documentation about using Long Poll requests for realtime updates.