Hey all, wanted to share an update on [Zippy](https://github.com/guzba/zippy) now that the library has improved a lot since my [original post](https://forum.nim-lang.org/t/7054#44558).
Some highlights: * Added support for opening, iterating over, extracting from and composing new Zip archives (.zip) and tarballs (.tar and .tar.gz). See [examples](https://github.com/guzba/zippy/tree/master/examples). The _extract examples show extracting the Nim source from a .tar.gz and .zip file and work well which is pretty cool to me. * Much much closer to zlib performance at both compressing and uncompressing (started off 3x slower at uncompressing for example, now 0% to 30% slower but sometimes faster too). This is an ongoing battle. See the repo for benchmarks. * Support for zlib compression levels -2 through 9 (-2: Huffman coding only, -1: default, 0: no compression, 1: best speed .. 9: best compression) * Wrote a PNG loader and writer which uses Zippy internally that lives in [Pixie](https://github.com/treeform/pixie/blob/master/src/pixie/fileformats/png.nim). This PNG writer has been used a lot and is working great, boosting my confidence in Zippy by seeing it work day after day. All of the above is of course in pure Nim! Tarballs and Zip archives have been tested between Windows and Mac, with the tar command and the OS utilities. Everything appears compatible and working well in my testing so hopefully it goes the same for anyone that can benefit from these new features. If you notice any issues or have any feedback, let me know here or GitHub.
