1 Linus On Specifications {anchor:Linus On Specifications} From {link:Kernel Trap|http://kerneltrap.org/node/5725} (and {link:Slashdot|http://linux.slashdot.org/linux/05/10/02/218233.shtml?tid=8&tid=106}). {quote}In a conversation that began as a request to include the SAS Transport Layer in the mainline Linux kernel, there was an interesting thread regarding specifications. Linux creator Linus Torvalds began the discussion saying, "a 'spec' is close to useless. I have _never_ seen a spec that was both big enough to be useful _and_ accurate. And I have seen _lots_ of total crap work that was based on specs. It's _the_ single worst way to write software, because it by definition means that the software was written to match theory, not reality." Linus went on to list two reasons to avoid specifications when writing software. First, "they're dangerously wrong. Reality is different, and anybody who thinks specs matter over reality should get out of kernel programming NOW." Second, "specs have an inevitable tendency to try to introduce abstractions levels and wording and documentation policies that make sense for a written spec. Trying to implement actual code off the spec leads to the code looking and working like CRAP." As a "classic example" he pointed to the OSI model, "we still talk about the seven layers model, because it's a convenient model for _discussion_, but that has absolutely zero to do with any real-life software engineering. In other words, it's a way to _talk_ about things, not to implement them. And that's important. Specs are a basis for _talking_about_ things. But they are _not_ a basis for implementing software." {quote} One problem is that you often get specifications when what you really need is either requirements or else working code (See Bill Joy's article on from "Protocols to Agents"). 2005-10-03 10:16:15.646 2005-10-03 10:16:15.646