ggplot2
What it is: R's most popular visualization library. Grammar of graphics—build plots layer by layer.
What It Does Best
Consistent syntax. Once you learn the logic, any plot type is easy. Add layers with +.
Publication quality. Beautiful defaults. Theme system for customization. Used in academic papers worldwide.
Statistical graphics. Built-in statistical transformations. Confidence intervals, smooth lines, regression fits with one line of code.
Pricing
Free. Open source, part of Tidyverse.
When to Use It
✅ You're working in R
✅ Need publication-quality static plots
✅ Statistical visualizations
✅ Want consistent, composable grammar
When NOT to Use It
❌ Need interactive charts (use Plotly)
❌ Don't know R (learn Python viz instead)
❌ Real-time dashboards (Shiny + Plotly better)
Bottom line: If you're in R, ggplot2 is the standard. Elegant, powerful, and backed by massive community. Learning curve pays off.