xlsgen was already fast. It just gets faster.

Build 3.0.0.58 of xlsgen includes a number of performance improvements. Both speed and memory are impacted.

Regarding speed, some of the performance improvements are related to reading large XLS and XLSX files. You can expect up to 25% in speed.

Regarding memory, some of the performance improvements are related to caching often used cell references when doing calculations. This is dramatic in large spreadsheets with many such formulas. You can expect up to 90% in less memory consumption (in addition to the accompanying lesser fragmentation).