Author of Brick, a collection of open-source libraries for PHP applications:

• brick/math : an arbitrary-precision arithmetic library
• brick/money : a money and currency library
• brick/date-time : a date and time library
• brick/phonenumber : a phone number library
• brick/geo : a GIS geometry library
• brick/varexporter : a powerful alternative to var_export()
• ...

and a few others.