SciDAVis vs AlphaPlot: Lineage, Differences, and Which to Pick

SciDAVis and AlphaPlot are not rivals — they are relatives. If their interfaces look familiar to each other, that is because they share most of their DNA. AlphaPlot’s own README states it plainly: AlphaPlot is a fork of SciDAVis 1.D009, which in turn was a fork of QtiPlot 0.9-rc2. This page explains the family tree honestly, compares the two as they stand today, and helps you pick — without talking either one down.

The family tree

The lineage runs QtiPlot → SciDAVis → AlphaPlot. SciDAVis was created when developers forked QtiPlot’s free 0.9 codebase; years later, Arun Narayanankutty forked SciDAVis 1.D009 to create AlphaPlot, which continues under his stewardship as a free, open-source (GPL-3.0) application for scientific data analysis and visualization on Windows, Linux, and macOS (mu-l/alphaplot on GitHub). AlphaPlot’s credits page even lists the SciDAVis and QtiPlot developers whose code it builds on — this is an acknowledged continuation, not a hostile split.

Side-by-side comparison

Dimension	SciDAVis	AlphaPlot
Lineage	Fork of QtiPlot 0.9-rc2	Fork of SciDAVis 1.D009
License	Free, open source (GPL)	Free, open source (GPL-3.0)
Development pace	Slow, volunteer maintenance cadence; latest source tag 2.9.2 (2022)	Actively developed: regular commits, CI test builds, Flatpak on Flathub
Codebase modernization	Older Qt-era codebase, stable but dated	Ongoing modernization (newer Qt, QCustomPlot for plotting)
Packaging	Installers for Windows/macOS, distro packages for Linux	Flatpak, AppImage-style distribution, Ubuntu PPA, test builds on its website
Documentation	Mature handbook with years of accumulated content	Manual based on the QtiPlot/SciDAVis manuals, still growing
Workflow	Shared Origin-style DNA: tables, matrices, plot windows, nonlinear fitting — skills transfer directly between the two
Project files	Do not assume files open in the other program — the formats have diverged since the fork. Keep a backup and treat each project’s files as native to the tool that created them.

Where they differ in practice

AlphaPlot’s strength is momentum. Because development never really stopped, it benefits from newer toolkit versions, modern distribution channels like Flatpak and its SourceForge releases, and continued bug fixing. If you are setting up a new lab workstation on a current Linux distribution, AlphaPlot’s packaging story is simply easier — a Flatpak install sidesteps the dependency archaeology that an older codebase can require.

SciDAVis’s strength is maturity and stability. Version 2.9.x is a known quantity: the feature set is fixed, the handbook documents it thoroughly, and a large body of tutorials (including this site’s tutorial collection) targets it directly. If you need a tool that behaves the same way this semester as it did last semester, that conservatism is a feature, not a bug.

Fitting and plotting capability are comparable — both descend from the same fit engine lineage, both produce publication-quality 2D plots, and both handle the standard table → plot → fit workflow. Neither one is “the powerful one” and the other “the weak one”; the differences are in packaging, pace, and polish.

Moving between the two

Because the workflow is shared, switching is mostly a matter of relearning where the menus live rather than learning new concepts. A few practical notes:

• Your data moves freely. CSV, ASCII tables, and image exports are identical on both sides — export tables from one and import them into the other with no loss.
• Project files do not. As noted above, the native project formats have diverged since the fork. Migrate by exporting data and rebuilding plots, not by opening one program’s project file in the other.
• Fit recipes transfer conceptually. A Gaussian peak fit with the same initial parameters will behave the same way in both programs, since they share the same fitting heritage — but re-verify the results rather than assuming identical numerics.
• Scripts may need tweaks. Both support Python scripting in the same tradition, but API details have drifted. Budget time to adapt automation scripts if you switch your production workflow.

Frequently asked questions

Is AlphaPlot really free? Yes. It is released under the GPL-3.0, with downloads on SourceForge and Flathub. There is no paid tier and no feature-locked “pro” edition.

Is AlphaPlot still being developed? Yes. Its repository shows ongoing commits, automated test builds, and packaged releases (Flatpak, Ubuntu PPA) — a markedly faster cadence than SciDAVis’s current maintenance pace. Check the commit history on GitHub if you want to confirm this yourself before committing to it.

Which one is more stable? SciDAVis 2.9.x, by virtue of barely changing. If your priority is “the tool behaves identically every time,” the slower-moving codebase wins. If your priority is “bugs I report might actually get fixed,” the actively developed fork wins.

Can I install both? Yes — they are separate applications. Install them in different directories and keep their project files separate.

Which should you pick?

• Pick SciDAVis if you want maximum stability, thorough documentation, and the tutorials on this site — and you are happy installing the classic packages. Download SciDAVis to get started.
• Pick AlphaPlot if you prefer the actively developed fork with modern packaging (Flatpak, current test builds) and don’t mind a younger manual.
• Trying both costs nothing. Because the workflow is nearly identical, an afternoon with each will tell you more than any comparison page can. Install them in separate directories and keep your project files separate.

Curious about the earlier generation? Our SciDAVis vs QtiPlot page covers the other side of the family tree, and alternatives surveys the wider field of free plotting tools.