Base modules are those that are installed by default.

Module Description
acorn A tiny, fast JavaScript parser.
base64 base64 encoding/decoding module (btoa, atob)
chai Chai is a BDD / TDD assertion module.
chartjs Chart.js is module for data visualization
codemirror CodeMirror is a versatile text editor for the browser. It is specialized for editing code, and comes with a number of language modes and addons that implement more advanced editing functionality.
crc The module for calculating Cyclic Redundancy Check (CRC)
crypto-js Library of crypto standards
datatable Advanced table UI contol.
dialog Dialog UI control.
dompurify DOMPurify is a DOM-only, super-fast, uber-tolerant XSS sanitizer for HTML, MathML and SVG
ds1621 ds1621 temperature sensor driver
encoding The Encoding API provides a mechanism for handling text in various character encodings, including legacy non-UTF-8 encodings. The API provides four interfaces: TextDecoder, TextEncoder, TextDecoderStream and TextEncoderStream.
events EventTarget is an interface implemented by objects that can receive events and may have listeners for them.
fifo Module for named pipes (a.k.a FIFO) 
file Module for representing file objects in web applications, as well as programmatically selecting them and accessing their data. This includes: File, FileReader, Blob, FileList
_File  
filesystem Filesystem interaction module
gui GUI library including most used standard controls such as button, icon, tab, accordion, etc.
i2c Module allows i2c access through the I2C /dev interface 
indexeddb Module for storage of significant amounts of structured data, including files/blobs.
jshashes Module implementing the most extended cryptographic hash function algorithms
jshint Module for flagging suspicious usage in programs written in JavaScript.
json-rpc A stateless, light-weight remote procedure call (RPC) module
later Library for defining recurring schedules and calculating future (or past) occurrences for them. Includes support for using English phrases and Cron schedules.
layout GUI control for defining the structure of the web appliation
mimetype File extension and mimetype assignment module
moment Date library for parsing, validating, manipulating, and formatting dates.
numbro Module for converting, formatting, and manipulating all your numbers, in more than 30 languages
numeral Module for formatting and manipulating numbers.
os Module for the usage of operating system dependent functionality.
path Module provides utilities for working with file and directory paths.
picker Advanced GUI controls such as, datepicker, colorpicker, etc.
pin  
pwm  
querystring  
richbox  
serial  
server  
sleep  
smtpclient  
socket  
subprocess  
tar  
terser  
tson  
ubjson  
uglifyjs  
upspico  
url  
webcomponent  
websocket  
web-streams  
Worker Enables the use of threads that execute JavaScript in parallel