This is a small dockapp, which shows the core temperature and cpu frequency from 2 upto 4 cores/cpus and the temperature of upto two thermal zones, which are normaly the motherboard temperature.
All cpus, which are supported by the linux kernel "coretemp" and "cpufreq" modules, could be monitored. f.e. core 2, atom and core ix.
All thermal zones which could be read from files are supported. f.e. ACPI through /sys/class/thermal/thermal_zoneX/temp or hardware sensors through /sys/devices/platform/<chip>/temp1_input.
To compile you must have libxcb (xcb-dev) installed.
The source is a single file with less than 1200 lines. The sources are (hopefully) good documented. They can be used as an example, how to write your own dockapp, applet or widget.
Started with version 2.04 the number of cpus and thermal zones can be configured. The background is no longer stored in the xpm; it is now dynamic generated. See older version for a simpler example.