Who are you, and what do you do?
My name is Sadayuki Furuhashi: a hacker who works hard to not work.
I'm the original author of MessagePack, an open source object serialization library. I'm also the author of Fluentd, a log collection tool. I recently co-founded Treasure Data, Inc., a cloud-based data warehousing and analytics service. I'm responsible for the design and implementation of the platform. My primary interest is in distributed systems: I strive to build complex yet practical distributed systems on top of fragile commodity servers.
What hardware do you use?
Computer: My only machine is a 13" MacBook Air. I switched my daily partner from Linux boxes to Mac laptops 5 years ago. I love Macs since they work well with both UNIX tools and Adobe software.
Peripherals: I have desktop setups at my home and at the office. I put the laptop into clamshell mode and connect it to a 27" Apple Thunderbolt Display. I use a Wacom Intuos tablet instead of a mouse. People are surprised to see me using a pen tablet for everything (from coding to surfing the web), but I like the ability to click any part of the screen directly (the tablet surface and display are mapped 1:1). I haven't used a mouse for 6 years. I use a Realforce keyboard and recommend it to all hackers. By the way, Kenneth Reitz uses Happy Hacking Keyboard PRO, another awesome keyboard with replacement key switches made by the same manufacturer.
I have two of each device so that I have the same configuration at home and at the office.
Servers: When I was a student, I built a "home datacenter" consisting of 8 servers so that I could research distributed systems without having to depend on school resources. With these servers (discreetly placed under my bed), I was able to implement the Kumofs and LS4 storage systems. With the decreasing price of physical servers, I think it's a very good time to be working on distributed systems.
There days I'm using Amazon EC2 instead of my own physical servers. There were advantages to having the hardware right there, but those servers were too noisy and hot to live with (imagine what happened when I ran benchmark scripts on all of these servers in my tiny apartment!). I think it's very good times to research even distributed systems because the price of physical servers is decreasing.
Headphones: I listen to music while coding in order to block out distractions. I've been using a JVC HA-FXC51 for a year now. Each time I buy a new pair, I'm impressed with how much the technology has progressed.
And what software?
I'm a traditionalist hacker and love using bash, vim, screen and many other small UNIX tools.
I use GitHub to publish code and communicate with collaborators. I test with Jenkins or Travis CI, and deploy to servers with Chef.
Because my open source work consists of performance-sensitive libraries, optimization work takes up a significant part of my free time. I used to use gperftools for performance profiling, but I have recently switched to Instruments (bundled with Xcode). Valgrind is another indispensable tool.
Ruby is my language of choice. I used to use C++, but I was enchanted by the flexibility of Ruby: it lets me focus on creating the proper design and architecture for the system. Java has an older style, but I sometimes use it to leverage the JVM (especially its garbage collector) and the multithread libraries. These features make Java one of the most mature platforms around. I'll also use C if I need it for performance optimizations.
As for desktop software, I use Chrome for the web and Sparrow for email. I use Numbers to draw diagrams quickly for documentation. It may come across as an odd choice, but it's simple and just works for me. I also use Illustrator to design websites (ex: msgpack.org) and use InDesign to edit articles.
Twitter is an important channel for communicating with open source collaborators. I use YoruFukurou on Mac OS X and Echofon on iPhone for clients. I use search tabs to look for feedback on my programs on Twitter.
I also like Gyazo, a simple tool to share screenshots quickly. It's like Gist for screenshots.
I want to mention Quicksilver as well, a small but awesome launcher utility.
What would be your dream setup?
If anything is possible, I want a magical compiler that turns designs in my brain into working code, but I am pretty happy with my current setup =)
Footnotes:
1: MessagePack now has a community for each language implementation, and development is modular. I oversee the overall direction and philosophy of the project, but development has been handed over to the experts of each language.
2: My home servers were built from cheap parts, with the exception of Intel PRO/1000 NIC, which was needed to boost network performance.