自打Web诞生那天起，数字货币就一直伴随着我们左右，像是Facebook Credits，一种允许你在Facebook应用内购买虚拟物品的数字货币，或者Microsoft Points，Xbox Live市场和Zune商店中的数字货币，你用美元兑换这些货币就和你把美元兑换成欧元，然后再用它们从卖家那里购买东西一样，从这个角度，一个法国的糕点店和Facebook上的FarmVille游戏并无区别。
昨天读到了 Bitcoin 的中文介绍，觉得非常有意思。不过上面这篇文章解释的非常不靠谱，我花了一晚上去Bitcoin的官方网站 仔细研究了一下，总算理解了其原理。感觉非常有启发，尤其是对虚拟货币的流通和发行有许多借鉴意义。今天写这篇 Blog 理一下。
Bitcoins are ordinarily only ever created in chunks of 50 at a time, with the whole 50 paid to a single person. Furthermore, the race to get the 50 BTC prize in a given block is highly competitive.
If you set out mining on your own, it may be a long time before you can make a return. Pooled mining allows you to receive smaller, more frequent, steadier payouts instead. If you have a slower computer, or a CPU miner, then pooled mining may be the only way that you will ever mine any bitcoins at all.
Here's what it has to offer:
It's fast – Phoenix implements the BFI_INT instruction, which can improve performance by 5-20%
It's as efficient as theoretically possible (that is, it doesn't discard any work unless that work would be invalid)
It's free, open-source software – It's available under the X11 license, and written in (fairly) well-documented and commented Python.
It loads kernels dynamically – If someone releases a more efficient kernel for our miner, it's as simple as dropping in the new kernel and using it.
It has a simple command-line interface – Obviously "simple" is subjective, but it's pretty easy to get started using.
It supports RPC w/LP and MMP, and provides plenty of stats – You can see our Multiminer server running here
This SQL Server tutorial is for anyone who wants to learn how to use SQL Server 2008. It assumes a basic understanding of databases and how they work.
If you don't currently have an understanding of how databases work, start with the basic database tutorial first. That tutorial covers the basic concepts of databases, so the examples in this tutorial will make more sense once you return here.
To get the most out of this tutorial, you should have a copy of SQL Server installed on your computer, so that you can go through the examples yourself. The examples in this tutorial are all done using the free version of SQL Server – SQL Server 2008 Express. You can download SQL Server 2008 Express from the Microsoft website (we'll get to that in a minute).
If you don't currently have SQL Server yet, that's OK. The tutorial is straight forward and contains plenty of screenshots.
Bitcoin 是最近热议的话题，不过中文资料非常少，这篇文章不会评论 Bitcoin 的意义和利弊，务求以尽简单的方式介绍什么是 Bitcoin，让更多人了解到这个有趣的创意。同时我会不断修正或补充内容，希望做到当有人问“什么是Bitcoin”时，只需把这篇文章的网址发给他就行了。@ivarptr
links for 2011-05-22