Turpentine is a Magento extension to improve Magento's compatibility with Varnish, a very fast caching reverse proxy. By default, Varnish doesn't cache requests with cookies, and Magento sends the frontend cookie with every request, causing a (near) zero hit rate for Varnish's cache. Turpentine provides Varnish configuration files (VCLs) to work with Magento and modifies Magento's behavior to significantly improve the cache hit rate.
Magento Knowledge Base extension has been developed by Fme that adds an FAQ section to each product page. It allows visitors to ask questions on the same product page under the FAQ tab, and merchants can answer those questions in accordion style, thus creating a pool of questions and answers which serve as a knowledge base for new visitors. Along with a FAQ for each product page, the extension creates a separate FAQ page for general Website questions related to shipping, payment, delivery, packaging etc. Other features include easy single click installation, SEO-friendly URLs, five different styles of the “ask a question” form and page, and CAPTCHA support.