11.Locks IsometricPattern

Public source code repositories, from Sourceforge to GitHub, from the Linux Kernel Archives to ReactOS.org, from PHP Packagist to the Python Package Index, better known as PyPI, are a fantastic source (sorry!) of free operating systems, applications, programming libraries, and developers’ toolkits that have done computer science and software engineering a world of good.

Most software projects need “helper” code that isn’t a fundamental part of the problem that the project itself is trying to solve, such as utility functions for writing to the system log, producing colourful output, uploading status reports to a web service, creating backup archives of old data, and so on.

In cases like that, you can save time (and benefit for free from other people’s expertise) by searching for a package that already exists in one of the many available repositories, and hooking that external package into your own tree of source code.

In the other direction, if you’re working on a project of your own that includes some useful utilities you couldn’t find anywhere else, you might feel inclined to offer something to the community in return by packaging up your code and making it available for free to everyone else.