Apache is a free and open-source cross-platform web server software.
Mod_fcgid is a high performance alternative to mod_cgi or mod_cgid, which starts a sufficient number instances of the CGI program to handle concurrent requests, and these programs remain running to handle further incoming requests.
OpenSSL is a software library for applications that secure communications over computer networks against eavesdropping or need to identify the party at the other end.
Unix is a family of multitasking, multiuser computer operating systems.
WhatsApp Business is a free to download app available on Android and iPhone using which businesses can connect with their customers.