PHP
MogifileFS is an open source distributed file system.
The company Verian rolled out Magento about a year back which is an open sourcee-commerce shopping cart platform.
The simplest way to start this topic is, PHPBB is hacked.
Semaphore is used to restrict access to shared resources, such as shared memory or to limit the number of processes that may simultaneously use a resource, in a multi-process or multi-threaded environment.
