Directory

Free, moderated open-access preprint server for physics, mathematics, computer science, statistics, quantitative finance, economics and related fields, with an open API and bulk access

Visual literature-exploration tool that builds a similarity graph of papers around a seed paper, with prior and derivative works lists

AI search engine over peer-reviewed literature that synthesizes answers, shows a Consensus Meter for yes/no questions and summarizes studies

Membership organization that registers DOIs for scholarly content and exposes the metadata through a free public REST API, content negotiation and the paid Metadata Plus service

AI research assistant that finds papers, extracts structured data from them into tables and runs systematic-review style workflows and reports

Free scholarly search engine from Google that indexes articles, theses, books and court opinions with citation counts and author profiles

Volunteer-run decentralized bibliographic database of economics research, fed by institutional archives and served through IDEAS, EconPapers, the Author Service, CitEc, NEP and MPRA

Literature-discovery app that grows collections of papers through citation and author networks and recommends related work, with a free-forever tier

Citation-analysis platform whose Smart Citations show whether later papers support, contrast or merely mention a claim, with an AI assistant and reference checking

Free AI-assisted literature search from Ai2 with an Academic Graph API, recommendations and downloadable datasets of papers, authors and citations