✦ This isn't a glossary anymore
A curated knowledge graph with editorial governance
A typical glossary gives you terms, definitions, and a search box. This goes further.
Terms are connected by reviewed, typed relationships, making it possible to follow how ideas relate across the entire corpus. Every connection is sourced, reviewed, and tracked, while the system continuously checks for missing links, dead references, and gaps in coverage.
The result is less a glossary and more a curated knowledge graph — designed not just to define concepts, but to show how they connect.
Honestly, we've stopped trying to pin down exactly what this is — and it's still being built. Depending on the day it reads like an Engineering Knowledge Operating System, a Curated Engineering Knowledge Graph, or an AI-Native Developer Knowledge Base, with a Blast Radius risk layer wiring in now. It's quietly becoming all of them — tap a ? to see what each means.
We're not quite sure what to call it — but it outgrew “glossary” a while ago.
The most ambitious framing: not a reference you read, but a substrate other tools run on. 819 reviewed, typed relationships bind the corpus into one coherent layer — alongside four-axis risk scores and editorial governance — that people browse and machines query. Engineering knowledge that's stored, connected, checked, and acted on all in the same place.
At its core it's a graph: 1,519 engineering concepts joined by reviewed, typed relationships. Every edge is sourced and tracked, every term scored on a four-axis risk model, and the whole corpus is continuously audited for missing links, dead references and gaps in coverage — closer to a maintained dataset than a wiki.
Built to be read by models as much as by people. The corpus is machine-readable end to end — typed edges, structured fields, an agent-sync layer, a deterministic assistant that answers from the graph instead of guessing, and 18 mediated narratives that walk through how distant concepts connect — so an LLM can traverse it the way a developer would.
The layer wiring in now. Every term already carries a four-axis risk score; Blast Radius teaches the graph to trace how that risk travels along its connections — turning isolated scores into a blast radius that shows how far a concept's risk actually reaches. Risk-graph readiness is at 40% and climbing as more connections are reviewed.
Glossary
A developer glossary, written to teach — built to be cited.
1.5k terms across 34 categories — definitions, examples, common mistakes and fixes. Authored under one editorial standard. Cross-linked, searchable, and openly crawled by AI agents.
Trending categories
AI citations · 7d
Popular tags
by term count
✦ Latest typed relationships
The graph is growing
Each edge is LLM-proposed, gate-filtered, and human-reviewed.
- URL & URLSearchParams API Often seen in AJAX Patterns for PHP Backends 1d
- URL & URLSearchParams API Often seen in Axios — HTTP Client for PHP APIs 1d
- Attack Surface Often seen in Penetration Testing 1d
- URL & URLSearchParams API Often seen in History API — SPA Routing with PHP Backend 1d
- URL & URLSearchParams API Often seen in Fetch API & HTTP Requests 1d
Garbage collection is the concrete piece of memory management that touches memory leaks directly: as a specialization of the heap-management side of the discipline, it's the runtime mechanism responsible for reclaiming unreachable objects. A leak is precisely what happens when that reclamation fails — most acutely in PHP when reference counting can't free circular references and the cycle collector is what stands between you and unbounded process growth. So the story from memory_management to memory_leak runs through GC because GC is the part of memory management whose success or failure determines whether allocations are ever returned.
Binary trees connect to pagination through database indexing, which is the structure that actually carries the benefit between them. The index is typically a B-tree variant of the binary tree concept, and its ordered, logarithmic-lookup structure is exactly what lets efficient pagination seek directly to a page's starting key (keyset pagination) instead of scanning and counting rows. Without the index sitting in the middle, the tree's ordering properties would never reach pagination at all — it's the index that translates tree structure into fast page boundaries.
Exactly-once delivery connects to domain events through the outbox pattern, which atomically writes those events to a database table in the same transaction as the business data that produced them. The pattern is what carries the events safely to the broker without loss or duplication, so the delivery guarantee is meaningfully about the domain events being relayed — remove the outbox and there's no mechanism tying the messaging guarantee to the architectural event records. That atomic write is the load-bearing piece: it's the bridge between 'something happened in the domain' and 'the broker delivers it exactly once'.
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Last 30 days
Agents 300
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Google 76
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PetalBot 148
SEMrush 57
Bing 56
ChatGPT 42
Ahrefs 34
Brave Search 31
DuckDuckGo 4
Applebot 1
Amazonbot 1
ChatGPT 13k
Amazonbot 12.8k
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Ahrefs 7.6k
SEMrush 6.1k
PetalBot 5.3k
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DuckDuckGo 31
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LinkedIn 2
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Most referenced terms
APCu — In-Process User Cache 4
readonly Classes (PHP 8.2) 3
Maintainability Index 3
Psalm Type Annotations 3
Network Sockets 3
Reverse Proxy vs Load Balancer 2
allow_url_fopen / allow_url_include 2
callable vs Closure vs First-Class Callable 2
Most active categories
How they use it
crawler 85.9k
crawler_json 5.8k
rag 1
pre-tracking
739
First ping
23 Mar 2026
Last 7 days
5.1k pings
Distinct agents
26
Unidentified
3k
AI Synthetic Data Generation
Using generative models to produce artificial training, testing, or augmentation data that mimics the statistical properties of real datasets without exposing originals.
t9
AI / ML intermediate
Block Cipher Modes
PHP 7.1+
How a block cipher (AES) processes data larger than one block — ECB is insecure, CBC requires a MAC, GCM provides authenticated encryption and is the correct choice.
t9
Cryptography advanced
Business Logic Abuse
Exploiting flaws in application workflows rather than technical vulnerabilities — bypassing payment steps, abusing discount codes, manipulating quantity fields, or racing concurrent requests.
t9
Security advanced
Business Logic Vulnerability
1
Flaws in application workflow allow attackers to abuse legitimate features in unintended ways.
CWE-840 OWASP A4:2021
t9
Security advanced
7.5
Cache Warming Strategies
PHP 5.0+
Pre-populating a cache before traffic arrives — preventing the cold-start thundering herd where every request misses a cold cache simultaneously after a deploy.
t9
Performance intermediate
Cache-Timing Side-Channel Attacks
PHP 5.6+
Attacks that infer secret information from response time differences — cached responses arrive faster than uncached ones, leaking whether a resource exists or a secret was correct.
t9
Security advanced
Cardinality in Observability
PHP 7.0+
The number of unique combinations of label values in a metric — high cardinality (millions of unique label combinations) causes memory exhaustion in time-series databases and is the most common observability scaling problem.
t9
Observability intermediate
Division by Zero & DivisionByZeroError
PHP 7.0+
PHP 7+ throws DivisionByZeroError for intdiv() and modulo with zero — but the / operator returns false or INF instead of throwing.
t9
PHP beginner
DOM Clobbering
Attack where injected HTML elements with controlled `id` or `name` attributes overwrite JavaScript globals or document properties, weaponising script-less HTML injection into code execution.
CWE-79 OWASP A3:2021
t9
Security advanced
6.5
Double URL Encoding Bypass
PHP 4.0+
Filters operating on URL-decoded input miss double-encoded payloads — %2527 decodes to %27 which decodes to ' — always decode completely before filtering.
t9
Security advanced
Elasticsearch Fundamentals
PHP 7.0+
A distributed search and analytics engine built on Lucene — storing documents as JSON, indexing them automatically, and providing a REST API for full-text search, aggregations, and real-time analytics.
t9
Search intermediate
Environment Variables
PHP 5.0+
1
Key-value pairs inherited by child processes — the standard way to pass configuration, credentials, and runtime settings to PHP applications without hardcoding.
t9
Linux intermediate
Eval Injection
PHP 5.0+
3
User input passed to eval() executes as PHP code, giving attackers full server-side code execution.
CWE-95 OWASP A3:2021
t9
Security intermediate
9.8
Event Loop Internals
PHP 8.1+ The mechanism that enables single-threaded async programs — a loop that checks for completed I/O events, runs their callbacks, then checks again.
t9
Concurrency advanced
extract() — Dangerous Variable Injection
PHP 4.0+
1
extract() creates local variables from an array, allowing attackers to overwrite existing variables if input is unsanitised.
CWE-621 OWASP A3:2021
t9
PHP beginner
9.8
Fetch API
ES2015
1
The browser-native Promise-based API for making HTTP requests — replacing XMLHttpRequest with a cleaner interface supporting streaming, CORS, and request/response objects.
t9
JavaScript beginner
Fetch API & HTTP Requests
ES2015
3
The modern browser API for HTTP requests — Promise-based, streaming-capable, and replacing XMLHttpRequest in all new code.
t9
JavaScript beginner
FormData API
ES2015
3
FormData constructs key-value pairs from HTML forms for AJAX submission to PHP backends — supports file uploads without page reload.
t9
JavaScript intermediate
GraphQL Schema Design
PHP 7.0+
Designing GraphQL schemas that are intuitive, evolvable, and performant — with clear type hierarchies, nullable conventions, and avoiding the N+1 query problem.
t9
API Design advanced
Host Header Injection
PHP 5.0+
1
A manipulated HTTP Host header is used by the application to generate URLs, enabling cache poisoning, password-reset hijacking, or SSRF.
CWE-116 OWASP A3:2021
t9
Security intermediate
7.5