Object-oriented programming (OOP) is one of the most popular paradigms used for building software systems. However, despite its industrial and academic popularity, OOP is still missing a formal apparatus similar to lambda-calculus, which functional programming is based on. There were a number of attempts to formalize OOP, but none of them managed to cover all the features available in modern OO programming languages, such as C++ or Java. We have made yet another attempt and created phi-calculus. We also created EOLANG (also called EO), an experimental programming language based on phi-calculus.

翻译：面向目标的编程(OOP)是用于建立软件系统的最受欢迎的范例之一,然而,尽管OOP在工业和学术上很受欢迎,但它仍然缺少一种正式的装置,类似于以功能性编程为基础的羊羔计算器。曾几次尝试将OOP正式化,但其中没有一次尝试涵盖了现代OO编程语言中的所有功能,如C++或爪哇。我们再次尝试并创建了phi计算器。我们还创建了EOLANG(也称为EO),这是一种基于双算法的实验性编程语言。