Authentication & Authorization
MarsCode
A free AI-powered cloud-based IDE
onelogin.com
Identity as a Service (IDaaS), Single Sign-On Identity Provider, Cloud SSO IdP, three company apps, and five personal apps, unlimited users
asgardeo.io
Seamless Integration of SSO, MFA, passwordless auth and more. Includes SDKs for frontend and backend apps. Free up to 1000 MAUs and five identity providers
duo.com
Two-factor authentication (2FA) for website or app. Free for ten users, all authentication methods, unlimited, integrations, hardware tokens
TabNine
Deep learning completion (part of codota)
OneCompiler
A versatile, AI-powered Online IDE supporting over 70+ programming languages, designed for developers to write, compile, and execute code seamlessly
logintc.com
Two-factor authentication (2FA) by push notifications, free for ten users, VPN, Websites, and SSH
Fine
Build Software with AI Agents. 
AWS cognito
AWS's authentication as a service
Userfront
Simplistic user authentication with pre-built back-office dashboard
Auth0
Authentication & authorization as a service
Authgear
Bring Passwordless, OTPs, 2FA, SSO to your apps in minutes. All Front-end included. Free up to 5000 MAUs