GRPN is a RPN calculator for the X Window system built using the GIMP Toolkit (GTK). GRPN works with real numbers, complex numbers, matrices, and complex matrices. Numbers can be displayed in 4 different radix modes, and complex numbers can be displayed in either Cartesian or polar form, in decimal or engineering notation.
geoPlugin is a PHP class that can get geographical information from an IP address using the geoPlugin Web service, also known as geolocation or geoIP. It takes a given IP address and sends a request to the geoPlugin Web services server to obtain the geographic location associated to the IP address. The class also retrieves the location's currency name and conversion rate relative to a given base currency. This can be used to convert a given amount of money to the local currency. It can also retrieve locations near a place given its latitude and longitude coordinates.