GTKWave is a mature desktop application for viewing waveform dump files generated by digital circuit simulators (VCD, FST, GHW, etc.). It provides a graphical interface with hierarchical signal browsing, time-synchronized waveform rendering, marker placement, pattern search, and transaction filtering. The tool also ships with multiple command-line utilities for format conversion (e.g., vcd2fst, fst2vcd) and signal mining. Its codebase is structured as a core GObject-based library (libgtkwave) that abstracts dump-file loading and querying, a set of helper libraries (libghw, libvzt, liblxt, libwcp, libjrb) for specific formats, and a GTK GUI layer (src/) that handles user interaction, rendering, and state. The project continues to receive active maintenance, with recent work including GSettings integration, WCP remote control protocol, and migration to Meson build system. However, the code retains significant global state (struct Global), platform-specific #ifdefs, and some duplicated VCD parsing logic across converters, which somewhat limits modularity and testability.