Blockscout is an open-source blockchain explorer for EVM-compatible chains, written in Elixir using the Phoenix framework. It indexes and serves on-chain data including blocks, transactions, internal transactions, token transfers, token balances, contract code, and more. The system is composed of four umbrella apps: `explorer` (database schemas, chain import pipeline, caching), `block_scout_web` (Phoenix web server with REST API v2, JSON-RPC, GraphQL, and real-time WebSocket channels), `indexer` (background fetchers that pull data from Ethereum nodes using JSON-RPC), and `ethereum_jsonrpc` (transport abstraction with chain-specific variants for Geth, Nethermind, Besu, etc.). The architecture is a monolith with clear separation of concerns, using PostgreSQL as the primary store, ETS/ConCache for caching, and Oban for async job processing. It supports multiple chain types (Ethereum, Optimism, Arbitrum, Celo, ZkSync, Scroll, and more) via compile-time and runtime configuration, with chain-specific data models and import pipelines. External dependencies include a PostgreSQL database, an Ethereum JSON-RPC endpoint, optional microservices for smart contract verification (Rust verifier, Sourcify), and third-party market data providers (CoinGecko, DefiLlama). The frontend is a single-page application built with jQuery and custom JavaScript, with real-time updates via Phoenix Channels. The codebase is well-structured with extensive use of Elixir behaviours (BufferedTask, Import.Runner, FillingMigration) and a sophisticated caching layer. It is actively maintained with frequent releases, thorough CI/CD, and a large community.
QTTabBar is a Windows Explorer shell extension that adds tabbed browsing, customizable toolbars, and a plugin system to File Explorer. It integrates as a COM band object (IDeskBand) into Explorer's rebar, providing features such as tab management, mouse gestures, keyboard shortcuts, folder groups, and a button bar. The architecture is a hybrid of WinForms and WPF, with heavy use of COM interop and native API hooking via the MinHook library. Key entry points include the BandObject base class, the QTCommandBar band, and the PluginServer that loads interactive and background plugins. External dependencies include the .NET Framework 4.8, Windows Shell APIs, and a native C++ hook library (QTHookLib). The system persists configuration in the Windows Registry and supports multi-language localization. While the codebase is mature and feature-rich, it exhibits technical drift due to reliance on legacy .NET Framework, extensive COM interop that may break on newer Windows versions, and some deprecated APIs. The plugin system and several utility components (e.g., PropVariant wrapper, ChineseCalendar) are well-crafted and potentially reusable in other projects.
FastCopy (published as RoboCopyEx, v1.2.1.0) is a Windows desktop utility that replaces Explorer's default copy/move/paste/delete with a robocopy-backed engine. In production it is three cooperating native components: a WinUI 3 (C++/WinRT, Windows App SDK 1.8) application that renders copy progress, a speed graph, pause/resume, duplicate-file conflict resolution and delete confirmations; a COM shell-extension DLL that adds copy/move/paste/delete items to both the new Windows 11 and legacy Explorer context menus; and a global keyboard-hook executable that intercepts Ctrl+V inside Explorer to route pastes through FastCopy. A fastcopy:// URI handler (CommandLineHandler) is the transport by which components pass operations to the main app. The solution is an MSIX package of six projects: FastCopy (UI), FastCopyShellExtension (Explorer COM DLL), FastCopyKeyboardHook (global hook EXE), RobocopyInjection (DLL injected into robocopy.exe to expose per-file progress), UnitTest, and SpeedTest — a TUI benchmark that empirically compares robocopy, xcopy, std::filesystem, IFileOperation and SHFileOperation. The central data flow: RobocopyViewModel builds robocopy arguments; RobocopyProcess launches robocopy.exe suspended inside a JobObject, injects a DLL to force English locale output, then streams the child's stdout through a regex-driven template parser (OutputRegexParseBase) while ProcessIOUpdater samples GetProcessIoCounters/GetSystemTimes to animate the Win2D speed graph, taskbar progress and Windows toasts. Settings are persisted via a WinRT IPropertySet-backed Settings class and MVVM runtime classes declared in IDL. Engineering quality is mixed and should be read from the code rather than the README's speed claims. The repo knowingly ships a crash after the window is closed; RobocopyInjectDll.h and CreateSuspend.h contain null-byte encoding corruption; numerous features are disabled ('Under development!') or commented out; and the app depends on a third-party WinUI3Package (essential:) control library plus dual vcpkg/NuGet dependency chains, making rebuilds fragile outside the author's machine. The DLL-injection and global-hook design is also the likely reason the Store rejected the package, per drama.md. The last commit (2026-09-19) indicates the project is still actively developed. Despite containing a benchmark harness and careful README performance tables, this is an application, not a data/research repository: there are no datasets, notebooks, or pipelines, and the SpeedTest project is an empirically driven engineering tool, not analysis. Its most durable artifacts are the independently extractable OS-interop helpers and parsing templates described below.