Best FlexSim Alternatives & Competitors in 2025

AnyLogic has changed simulation modeling and expanded its application into complex business environments. The unmatched flexibility of multimethod modeling allows users to capture the complexity of virtually any system, at any level of detail.

Key AnyLogic features:

Multi-method Modeling Extensive Libraries User-friendly Interface Integration Capabilities

freemium

a discrete-event network simulator for internet systems.

Key ns-3 features:

Open Source Realistic Simulation Active Community Wide Range of Protocols

Open Source

PlexTrac is the #1 AI-powered platform for pentest reporting and threat exposure management, helping cybersecurity teams efficiently address the most critical threats and vulnerabilities.

Key PlexTrac features:

Comprehensive Reporting Collaboration and Integration Centralized Vulnerability Management User-Friendly Interface

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NetSim software was created to simulate various Cisco systems. Cisco software is known around the world as being one of the best network, routing and switch systems for businesses and private use. Read more about NetSim.

Key NetSim features:

Comprehensive Lab Exercises Realistic Network Simulations Learning Mode and Skill Building Versatility

Paessler Multi Server Simulator is inexpensive and robust software that helps you power massive-scale testing.

Key Paessler Multi Server Simulator features:

Scalability Flexibility Ease of Use Cost-Effective

Mininet is a robust and inexpensive Instant Virtual Network designed to function on standard PCs like Laptops and Desktops.

Key Mininet features:

Ease of Use Cost-Effective Rapid Prototyping Scalability

Open Source

Cloonix is an open-source virtual network creation framework based on KVM licensed under the AGPLv3 license.

Key Cloonix features:

User-Friendly Interface Flexible Network Emulation Open Source Lightweight Solution

Actran is a finite element-based simulation software to analyze the acoustic behavior of mechanical systems and parts.

Key Actran features:

Advanced Acoustic Simulation High-Performance Computing Extensive Material Library Customizable Interface

Cisco VIRL is a next-gen network virtualization and orchestration platform that enables you to accomplish multiple tasks like creating and customizing simulated networks with third-party and Cisco objects by means of a graphical utility.

Key Cisco VIRL features:

Realistic Network Simulations Comprehensive Device Support Scalability Educational Resources

VNX is a simple, fast, and highly effective virtualization tool developed to assist you in creating virtual network testbeds automatically, resulting in time-saving.

Key VNX features:

Cost-effective virtualization Flexibility Educational Use Community Support

A high-level language and interactive environment for numerical computation, visualization, and programming.

Key MATLAB features:

Versatility Built-in Functions User-Friendly Interface Excellent Visualization

Mathematica has characterized the cutting edge in specialized processing—and gave the chief calculation environment to a large number of pioneers, instructors, understudies, and others around the globe.

Key Wolfram Mathematica features:

Comprehensive Functionality High-Level Programming Language Integrated System Strong Community & Support

IMUNES is a cost-effective and efficient Integrated Multiprotocol Network Simulator/Emulator that functions as a tool for Linux and FreeBSD.

Key IMUNES features:

Versatile Network Emulation Real-time Operation Open Source Lightweight Virtualization

OPNET is a next-gen and highly resourceful network simulator tool that enables engineers and other professionals to simulate the performance and output of any network type.

Key OPNET features:

Comprehensive Simulation Capabilities Validated Models Detailed Performance Analysis Wide Range of Network Elements