🤖 Overview

Larbin is a lightweight, open-source web crawler originally developed by Sebastien Ailleret and published under the GNU General Public License (GPL). Its primary purpose is to provide a simple, efficient crawling engine for research, personal projects, or small-scale indexing tasks. Unlike commercial search engine bots, larbin is designed for experimentation and is often used in academic environments to study crawling algorithms, network performance, or to fetch a subset of the web for analysis. It does not feed data into a specific commercial product but rather serves as a tool for developers and researchers who need a configurable crawler.

🌐 Technical Behavior

Larbin operates as a single-threaded, event-driven crawler that uses non-blocking I/O (based on the poll() system call) to manage multiple simultaneous connections without heavy resource usage. Its crawl pattern typically follows a breadth-first strategy by default, prioritizing pages within the same domain before moving to external links. The bot sends requests sequentially or in parallel based on its configuration; typical default settings allow up to 100 concurrent connections per site. Larbin does not maintain a fixed IP range — it uses the IP address of the machine it is deployed on, which can vary widely. It supports HTTP/1.1 and respects the robots.txt default policy if enabled during compilation. The crawler stores fetched pages as plain text files on disk, often organized by hostname.

📋 robots.txt Compliance

According to the official documentation and source code on GitHub (https://github.com/larbin/larbin), larbin includes a built-in robots.txt parser that is enabled by default. It honors Disallow directives and respects Crawl-delay directives when configured. However, the parser is a minimal implementation — it does not handle wildcards or complex patterns as robustly as modern crawlers. Users can also disable robots.txt compliance by recompiling the software with a different flag, which is a documented feature for controlled testing environments.

🔍 Detection Indicators

Larbin identifies itself via the User-Agent string: "larbin/2.6.3" or similar version suffixes (e.g., "larbin/2.6.2"). The exact string may vary depending on the compilation. It sends a standard Accept header of "*/*" and typically does not include custom headers. Behavioral fingerprints include a low request rate (often 1-5 requests per second) compared to commercial bots, and an absence of JavaScript parsing or rendering capabilities. It does not fetch images or other embedded resources unless explicitly configured.

📊 Data Usage

The data collected by larbin is stored locally as raw HTML files. It is used primarily for research purposes — such as analyzing web link structures, testing crawling strategies, or building custom search indexes for private datasets. Since larbin is not tied to any commercial service, its output is entirely under the control of the operator. Some academic papers (e.g., "Larbin: A Simple Web Crawler" by Ailleret) cite its use for benchmarking network performance and link graph analysis.

⚙️ Rate Limiting Policy

Larbin is rate-limited not because it is malicious, but because its aggressive default parallelism (up to 100 simultaneous connections per site) can inadvertently overwhelm smaller servers or shared hosting environments. The policy rationale for threshold-based blocking is to protect backend resources from excessive load while still allowing legitimate, low-frequency crawling by researchers who properly configure the Crawl-delay setting.

ⓘ Data Notice: The information presented above has been compiled from publicly available internet sources. Boteraser aggregates this data solely for informational purposes and does not independently classify, evaluate, or endorse any findings about the bots listed. The accuracy and completeness of this information is the sole responsibility of the original publishers. Boteraser and its operators accept no liability for any decisions made based on this data.