The fourth in the Architecture of Open Source Applications series.

| No | Title | Author | Keywords | 읽은 사람은 이름과 소감을 적어봅시다. |
|---|---|---|---|---|
| 0 | Introduction | Michael DiBernardo | ||
| 1 | Blockcode | Dethe Elza | html/css/javascript | fred |
| - A visual programming toolkit | ||||
| 2 | A Continuous Integration System | Malini Das | python | fred |
| 3 | Clustering by Consensus | Dustin J. Mitchell | fred? | |
| 4 | Contingent | Brandon Rhodes and | ||
| - A Fully Dynamic Build System | Daniel Rocco | |||
| 5 | A Web Crawler | A. Jesse Jiryu Davis | python | fred |
| With asyncio Coroutines | and Guido van Rossum | |||
| 6 | Dagoba: an in-memory graph database | Dann Toliver | ||
| 7 | DBDB: Dog Bed Database | Taavi Burns | ||
| 8 | An Event-Driven Web Framework | Leo Zovic | ||
| 9 | A Flow Shop Scheduler | Dr. Christian Muise | ||
| 10 | An Archaeology-Inspired Database | Yoav Rubin | ||
| 11 | Making Your Own Image Filters | Cate Huston | java | fred |
| 12 | A Python Interpreter | Allison Kaptur | python | fred |
| Written in Python | ||||
| 13 | A 3D Modeller | Erick Dransch | ||
| 14 | A Simple Object Model | Carl Friedrich Bolz | ||
| 15 | Optical Character Recognition (OCR) | Marina Samuel | ||
| 16 | A Pedometer in the Real World | Dessy Daskalov | ruby | |
| 17 | The Same-Origin Policy | Eunsuk Kang, | ||
| Santiago Perez De Rosso, | ||||
| and Daniel Jackson | ||||
| 18 | A Rejection Sampler | Jessica B. Hamrick | ||
| 19 | Web Spreadsheet | Audrey Tang | angularJS (+web) | fred |
| 20 | Static Analysis | Leah Hanson | ||
| 21 | A Template Engine | Ned Batchelder | python | fred |
| 22 | A Simple Web Server | Greg Wilson | python | fred |