Alpine Linux
Alpine Linux is a community developed operating system designed for routers, firewalls, VPNs, VoIP boxes, containers, and servers. It was designed with security in mind; it has proactive security features like PaX and SSP that prevent security holes in the software to be exploited.
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Synex
Synex is a GNU/Linux distribution based on Debian's "Stable" branch, developed with the official Debian Live Build tool. It offers four separate desktop options with GNOME, LXDE, KDE Plasma and Xfce, all of which are composed of a rather frugal set of applications in its default state, without any development tools or offices suites.