Steps Toward the Reinvention of Programming

科学使用模型不仅是为了表达理论，也是为了思考。如果模型足够强大，可以捕捉到现象，并且足够小，可以理解，那么这些模型就是最有用的。这在计算的权宜之计世界中做得还不够，在这个世界中，工件往往是功能性的，而不是可理解的。今天的许多编码都使用60年代的技术，通常会产生数百万行代码。但直觉熵的感觉坚持认为，与代码大小相比，数学内容很小。环境不仅仅是用来使用的，也是用来生活和学习的。因此，自我解释的进步将提升软件工程（一个可公开的系统将对实际编程有很大的用处）和计算机科学（对可理解性和公开的要求将自然地导致更好、更高层次的计算结构的发明）。这反过来又会提升设计（所有级别的可见系统都应该是干净、紧凑、强大、简单和美观的，而不是肮脏和笨重的）。PI长期而辉煌的研究生涯结合了计算机科学（面向对象编程，反射整体系统和网络），UI（重叠窗口和图标），教育（特别是儿童），设计（追求美以及解决问题）和计算机工程（学习如何有效地制作整个硬件/软件系统）的兴趣和发明。与标准做法相比，他开发的替代系统规模较小。例如，Squeak在约2.8MB（约20万行）的代码中涵盖了大部分个人计算（包括其自身的应用程序、操作环境、UI和开发工具等）。经过精心的新设计，PI有信心可以缩小10倍或更多。在这个项目中，PI和他的团队将设计并构建一个极其紧凑和实用的整个个人计算系统模型，包括操作系统、开发工具、图形用户界面、应用程序、媒体、最终用户编程、互联网通信、共享和媒体（类似于web++）——作为一个“探索博物馆”，它本身可以很容易地被青少年理解。动态架构的每个部分都将使用全新的或新改编的强大思想，这些思想应该有助于提高对如何从金属到UI和应用程序设计和构建整个系统的理解；许多小型模型将来自于将“多”抽象为“一”和其他特殊的数学方法。这笔资金是为了支持这个大型项目的中心部分（它被划分为一个完整而有趣的系统，将由NSF单独支持）。开发的软件将在多个平台上自由传播，并将在中小学和大学进行广泛的用户测试。一个关键的平台将是动力不足的“100美元笔记本电脑”，这是对该系统实用深度的严峻考验。更广泛的影响：大多数编程的早期学习都是以一种不可伸缩的方式完成的，有点类似于用钉子和木板拼凑一个狗窝。我们学到的东西不能以5倍的倍数扩展，更不用说100倍以上的倍数了。更关键的是，计算机领域最强大的思想的深层次的数学性质没有得到很好的描述，也没有通过论文来学习，即使读了也很难理解。制作一个设计良好的系统，同时还能促进学习和促进变化，这将对计算机的许多领域产生巨大而积极的影响。它将构成一个“系统就是课程”的例子，用于学习许多重要而有力的思想，特别是青少年和大学生，他们构成了未来的程序员，他们将找到方法，充分利用一种更简单但更强大的个人计算方法。

Science uses models not just to represent theories, but to think with. The models are most useful if they are powerful enough to capture the phenomena, and small enough to be comprehensible. This is not done enough in the expedient world of computing, where the artifacts tend to be functional rather than understandable. Much coding today uses techniques from the 60s, often resulting in millions of lines of code. But one's sense of intuitive entropy insists the mathematical content is tiny compared to the code size. Environments are not just used, but also lived in and learned. So advances in self-explanation would lift both software engineering (a disclosable system would be of great utility for practical programming) and computer science (the requirements for understandability and disclosure would naturally lead to the invention of better and higher level computational structures). These in turn would lift design (the visible system at all levels should be clean, compact, powerful, simple, and pretty, not dirty and ponderous). The PI's long and illustrious research career has combined interests and inventions in computer science (object-oriented programming, reflective whole systems, and networking), UI (overlapping windows and icons), education (particularly for children), design (striving for beauty as well as problem solving), and computer engineering (learning how to efficiently make whole hardware/software systems). The alternative systems he has developed have been small in comparison with standard practice. Squeak, for example, covers much of personal computing (including its own applications, operating environment, UI and development tools, etc.) in ~2.8MB of code (about 200,000 lines). With a careful new design the PI is confident it could be smaller by a factor of 10 or more. In this project the PI and his team will design and build an extremely compact and practical model of an entire personal computing system from the metal upwards, including the equivalents of an operating system, development tools, graphical user interface, applications, media, end-user programming, and internet communications, sharing and media (analogous to the web++) - as an "Exploratorium" for itself that can be readily understood by teenagers on up. Each part of the dynamic architecture will use wholly new or newly adapted powerful ideas that should help advance understanding of how to design and build whole systems from the metal up through UI and applications; much of the small model size will derive from abstracting "the many" into "the one" and other special mathematical approaches. This funding is for support of the central part of this large project (which is partitioned so that a complete and interesting system will result from the NSF support alone). The software developed will be freely disseminated on multiple platforms, and extensive user testing will be conducted in schools and universities. A key platform will be the under-powered "$100 laptop", an acid test of the pragmatic depth of the system.Broader Impacts: Most early learning of programming is done in a non-scalable way, somewhat equivalent to banging together a doghouse with nails and planks. What is learned doesn't scale well by a factor of 5, let alone by factors of 100+. Even more critically, the deeper mathematics-like nature of the most powerful ideas in computing is poorly described and learned via papers, which even if they are read are often difficult to understand. Making a well-designed system that is also instrumented to promote learning and to facilitate changes will have a dramatic and positive impact on many areas of computing. It will constitute an example of "the system is the curriculum" for learning many important and powerful ideas, especially by teenagers and university students who comprise tomorrow's programmers, and who will find ways to make great use of a simpler yet stronger approach to personal computing.