Creates a hyperlink to a Uniform Resource Locator

<a href="URL">clickable text</a>

Creates a hyperlink to an email address

<a href="mailto:EMAIL_ADDRESS">clickable text</a>

Creates a target location within a document

<a name="NAME">

Creates a link to that target location

<a href="#NAME">clickable text</a>

Graphical elements

Inserts a horizontal rule


Sets size (height) of horizontal rule

<hr size=?>

Sets width of rule (as a % or absolute pixel length)

<hr width=?>

Creates a horizontal rule without a shadow

<hr noshade>

Adds image; it is a separate file located at the URL

<img src="URL" />

Aligns image left/right/center/bottom/top/middle (use CSS)

<img src="URL" align=?>

Sets size of border surrounding image (use CSS)

<img src="URL" border=?>

Sets height of image, in pixels

<img src="URL" height=?>

Sets width of image, in pixels

<img src="URL" width=?>

Sets the alternate text for browsers that can't process images (required by the ADA)

<img src="URL" alt=?>

Text Tags

Creates preformatted text

<pre> </pre>

Creates headlines -- H1=largest, H6=smallest

<h1> </h1> --> <h6> </h6>

Creates bold text (should use <strong> instead)

<b> </b>

Creates italicized text (should use <em> instead)

<i> </i>

Creates typewriter-style text

<tt> </tt>

Used to define source code, usually monospace

<code> </code>

Creates a citation, usually processed in italics

<cite> </cite>

Creates address section, usually processed in italics

<address> </address>

Emphasizes a word (usually processed in italics)

<em> </em>

Emphasizes a word (usually processed in bold)

<strong> </strong>

Sets size of font - 1 to 7 (should use CSS instead)

<font size=?> </font> 

Sets font color (should use CSS instead)

<font color=?> </font>

Defines the font used (should use CSS instead)

<font face=?> </font>


Creates an unordered list


Creates an ordered list (start=xx, where xx is a counting number)

<ol start=?></ol>

Encompasses each list item


Creates a definition list


Precedes eachdefintion term


Precedes eachdefintion



Creates a new paragraph


AInserts a line break (carriage return)


Puts content in a quote - indents text from both sides


Used to format block content with CSS


Used to format inline content with CSS


Basic Tags

Creates an HTML document

<html> </html>

Sets off the title & other info that isn't displayed


Sets off the visible portion of the document


Puts name of the document in the title bar; when bookmarking pages, this is what is bookmarked



dplyr cheat sheet is a quick reference for dplyr that is a grammar of data manipulation, providing a consistent set of verbs that help you solve the most common data manipulation challenges.


A regular expression is a sequence of characters that specifies a search pattern.


PySpark is an interface for Apache Spark in Python. It not only allows you to write Spark applications using Python APIs


Go is a statically typed, compiled programming language designed at Google by Robert Griesemer, Rob Pike, and Ken Thompson.


Watchman exists to watch files and record when they change. It can also trigger actions (such as rebuilding assets) when matching files change.


Rollup Rollup is a module bundler for JavaScript which compiles small pieces of code into something larger and more complex, such as a library or application.


Bluebird is a fully-featured Promise library for JavaScript. The strongest feature of Bluebird is that it allows you to "promisify" other Node modules in order to use them asynchronously. Promisify is a concept applied to callback functions.


Flow is a static type checker for your JavaScript code. It does a lot of work to make you more productive. Making you code faster, smarter, more confidently, and to a bigger scale.

Node.Js Api

Node.js® is a JavaScript runtime built on Chrome's V8 JavaScript engine.

C Preprocessor

Quick reference for the C macro preprocessor, which can be used independent of C/C++.


Sass is a preprocessor scripting language that is interpreted or compiled into Cascading Style Sheets. SassScript is the scripting language itself. Sass consists of two syntaxes.


Active Admin is a Ruby on Rails plugin for generating administration style interfaces. It abstracts common business application patterns to make it simple for developers to implement beautiful and elegant interfaces with very little effort.


The Fetch standard defines requests, responses, and the process that binds them: fetching.


$ http POST http://example.com name="John" Host:example.com — JSON, cookies, files, auth, and other httpie examples.


RSpec is a computer domain-specific language testing tool written in the programming language Ruby to test Ruby code. It is a behavior-driven development framework which is extensively used in production applications.


Sauce Labs allows users to run tests in the cloud on more than 700 different browser platforms, operating systems, and device combinations.


Jasmine is a behavior-driven development framework for testing JavaScript code.


Sequelize is a promise-based Node.js ORM for Postgres, MySQL, MariaDB, SQLite and Microsoft SQL Server.


Ubuntu is a Linux distribution based on Debian and composed mostly of free and open-source software. Ubuntu is officially released in three editions: Desktop, Server, and Core for Internet of things devices and robots.

Rails Models

Ruby on Rails, or Rails, is a server-side web application framework written in Ruby under the MIT License. Rail is a model–view–controller framework, providing default structures for a database, a web service, and web pages.

Git Log

Git is software for tracking changes in any set of files, usually used for coordinating work among programmers collaboratively developing source code during software development.


Ruby on Rails, or Rails, is a server-side web application framework written in Ruby under the MIT License. Rails is a model–view–controller framework, providing default structures for a database, a web service, and web pages.

Ansible Examples

Ansible is an open-source software provisioning, configuration management, and application-deployment tool enabling infrastructure as code.

Bolt Quickstart

A quick guide to getting started writing Bolt tasks


RSpec Rails defines ten different types of specs for testing different parts of a typical Rails application.


rsync is a utility for efficiently transferring and synchronizing files between a computer and an external hard drive and across networked computers by comparing the modification times and sizes of files.

Ledger Cli

Ledger is a command-line based double-entry bookkeeping application. Accounting data is stored in a plain text file, using a simple format, which the users prepare themselves using other tools.


Homebrew is a free and open-source software package management system that simplifies the installation of software on Apple's operating system macOS as well as Linux.


Bundler provides a consistent environment for Ruby projects by tracking and installing the exact gems and versions that are needed.