Most complete Modbus library for Arduino. A library that allows your Arduino board to communicate via Modbus protocol, acting as a master, slave or both. Supports network transport (Modbus TCP) and Serial line/RS-485 (Modbus RTU). Supports Modbus TCP Security for ESP8266/ESP32.

Open ModScan is a Free Modbus Master (Client) Utility

PHP client for Modbus TCP and Modbus RTU over TCP (can be used for serial)

EasyModbusTCP library for Java implementation

Modbus client for ESP32

ModbusTools are cross-platform (Windows, Linux) Modbus simulator tools (client and server) with GUI to work with Modbus protocol (TCP,RTU,ASCII)

A library to implement the master/client portion of the Modbus RTU protocol on Arduino

Modbus TCP client library to interact with Modbus servers such as PLCs.

Modbus RTU packet sniffer

Modbus master and slave implementation in C++

A Modbus client in Go

Modbus client (TCP/RTU) over TCP/Serial for Go

Java implementation of MODBUS TCP client for master devices.

A thread safe Modbus Client using idiomatic Go concurrency design patterns.

Modbus TCP Client/Server

A Modbus client visualizing data from remotes on a single web page

Modbus client library for .NET

Raspberrypi Pymodbus TCP with Slave ESP8266 Nodmcu

Modfuzz: A simple python based Modbus Client to carry out transactions from the command line.

A simple python script to automate the modbus address value enumerations