Hyung-Hwan Chung is a systems programmer and long-time open-source developer. His work stays close to the foundations of software—language runtimes, portable C libraries, asynchronous I/O, network services, and the tools needed to operate them.
His public open-source trail reaches back at least to 2009, when he introduced QSEAWK as an embeddable interpreter with a flexible API and minimal platform dependencies. Those priorities continue in today's projects: software that gives an application tighter control without hiding the underlying system.
His contributions also extend beyond his own repositories. The official PECL Subversion changelog credits Chung with fixes and additions covering revision handling, UTF-8 validation, property APIs, repository transactions, memory safety, and portability across machine architectures.
Across this work is a practical approach to engineering: understand the low-level mechanism, make it reusable, and leave the implementation open for others to inspect.
Active work
A continuing thread through the work.
The active work spans language runtimes, asynchronous systems foundations, and practical networking tools. Hawk and Hak explore programmable engines, HIO provides reusable low-level components, and Hodu carries those systems ideas into remote access. Across them runs the same question: how can a complex capability become a clean, portable component?
01
Hawk · Hak
Languages built to live inside systems.
Hawk is the mature side of the language work: a portable AWK interpreter that runs as a command-line tool or embeds into C and C++ applications. It has its own focused runtime, extension modules, and application-facing API.
Hak is the exploratory counterpart. Its compact command-language syntax supports functions, classes, message sends, collections, and other higher-level runtime ideas. Together, Hawk and Hak investigate how much expressive power can fit inside a small, controllable engine.
02
HIO
Build the asynchronous foundation.
HIO works closer to the operating system. It brings sockets, pipes, processes, pseudo-terminals, timers, and event multiplexing under one asynchronous interface, then builds service components for HTTP, FastCGI, DNS, and DHCP on top.
This is the reusable center of the active systems work: isolate platform details, keep control of resources explicit, and give network services a dependable event-driven base.
03
Hodu
Carry the systems work across networks.
Hodu turns low-level networking concerns into a deployable client–server tool. It connects services across network boundaries through TCP forwarding, HTTP-oriented proxies, browser-accessible pseudo-terminals, and SSH terminal sessions.
Where Hawk, Hak, and HIO concentrate on engines and foundations, Hodu follows the same principles outward into an operational service: small components, explicit control, and practical access to remote systems.
04
Earlier work
Projects that formed the path here.
QSE was a broad systems library containing embeddable AWK and sed engines alongside HTTP and foundational utilities. Its AWK work later continued in the more focused Hawk project; QSE itself is now largely inactive.
Codepot brought Subversion repositories, documentation, issues, and releases together in a web workspace. It represents an earlier chapter of practical developer tooling and is no longer under active development.
Moo remains an experimental, Smalltalk-influenced language implementation. For now it serves mainly as a reference while a future rewrite is considered.