Marlin opens multi-gigabyte files that cause other text editors to crash or freeze.
Memory-Mapped I/O Architecture
A huge file is mapped and its line index is built off the main thread. The welcome sheet is the product statement: people who open 2 GB files and expect them to just open.
Sparse Indexing & Windowed Scrolling
Go to Line is ⌘J. The status bar shows the line, the column, the language, the encoding, the line ending, and the indent.
Large-File Safety Thresholds
A read-only document can still be sorted by adding the sort to the pipeline. The Sort Lines sheet says so: the file is read-only, add the sort to the pipeline instead.