Bootstrap is a free and open-source CSS framework directed at responsive, mobile-first front-end web development. It contains CSS and JavaScript-based design templates for typography, forms, buttons, navigation, and other interface components.
Elfsight is an all-in-one platform offering 70+ customisable widgets for websites.
Mobirise is a free offline app for Windows and Mac to easily create small/medium websites, landing pages, online resumes and portfolios.
Nginx is a web server that can also be used as a reverse proxy, load balancer, mail proxy and HTTP cache.
WhatsApp Business is a free to download app available on Android and iPhone using which businesses can connect with their customers.