Academia.edu is an American for-profit social networking website for academics. It began as a free and open repository of academic journal articles and registered a .edu domain name when this was not limited to educational institutions. The site was launched in September 2008.
ResearchGate is a European commercial social networking site for scientists and researchers to share papers, ask and answer questions, and find collaborators.
LinkedIn is an American business- and employment-oriented online service that operates via websites and mobile apps. Launched on May 5, 2003, the platform is primarily used for professional networking and career development, and allows job seekers to post their CVs and employers to post jobs.
SlideShare is an American hosting service, now owned by Scribd, for professional content including presentations, infographics, documents, and videos. Users can upload files privately or publicly in PowerPoint, Word, PDF, or OpenDocument format.