Pencil is a standalone app that lets you create diagrams or UI mockups. It doesn't have collaboration/multi-user features.
Cost / License
- Free
- Open Source (GPL-2.0)
Application type
Alerts
- Discontinued
Platforms
- Mac
- Windows
- Linux
- PortableApps.com




fluidIA is described as 'FluidIA is an emerging agile design tool for prototyping rich user interfaces. This web based tool allows for rapid refinement and exploration of concepts using an object-oriented approach to design' and is a Prototyping tool. There are more than 10 alternatives to fluidIA, not only websites but also apps for a variety of platforms, including Windows, Mac, iPhone and iPad apps. The best fluidIA alternative is Pencil Project, which is both free and Open Source. Other great sites and apps similar to fluidIA are Lucidchart, Microsoft Visio, OmniGraffle and Wondershare EdrawMax.
Pencil is a standalone app that lets you create diagrams or UI mockups. It doesn't have collaboration/multi-user features.




Lucidchart is a cloud-based platform that promotes teamwork through diagramming, collaboration, and data visualization. It serves millions worldwide, offering flowcharts, UML, real-time collaboration, Visio support, and browser access. Designed for innovation and understanding, it integrates easily into workflows.




Create data-connected diagrams with real-time collaboration as part of the Office Suite. Ideal for IT and business professionals, it visualizes complex info with ease, providing intuitive tools for diagramming, mind mapping, and vector graphics.

OmniGraffle can help you make eye-popping graphic documents—quickly—by providing powerful styling tools, keeping lines connected to shapes even when they’re moved, and magically organizing diagrams with just one click.




Versatile diagram software offering extensive templates for flowcharts, org charts, and more. AI integration simplifies diagramming, facilitates project analysis, and includes features like chatbots and OCR. Suitable for personal, professional, and collaborative use.




A streamlined web app that helps you create and collaborate in real-time on wireframes, mockups, diagrams and prototypes.




Axure RP is the leading tool for rapidly creating wireframes, prototypes and specifications for applications and web sites.




A collaborative design tool offering wireframing, prototyping, and design specs creation in a single browser-based platform. Integrate seamlessly with your workflow via API, sync with Sketch and Photoshop, and utilize a vast library of assets. Streamline design-to-dev with automated code generation.




VSD Viewer opens Visio drawings directly on a computer without conversion on external Web Servers. Viewing Visio documents is as simple as dragging and dropping off files (with a .vsd, .vsdx, .vdx extension) to the Application window.




WireframeSketcher is a software tool that helps product managers, designers and developers quickly create wireframes, mockups and prototypes for desktop, web and mobile applications. It’s standalone software and a plug-in for any Eclipse IDE.




ProcessMaker is a cost effective and easy to use open source business process management (BPM) or workflow software application.




Diagramo is an online flowchart software
