# Help On Mosaic Version 2.1

If you have accessed this document from the Help On Version menu selection in NCSA Mosaic, you are using version 2.1.

If you have not used a 2.x version of Mosaic before, you should first read Help On Version 2.0 for an overview of things that have changed since version 1.2.

Version 2.1 includes the following changes from version 2.0:

- Remote control users and script writers take note: control filename changed from `/tmp/xmosaic.pid` to `/tmp/Mosaic.pid`. This is the final such change, forever.
- Transparent uncompression over HTTP/1.0 is working -- Plexus 3.0i-beta is known to handle the server-side aspects, and the first release of NCSA httpd after 1.0a5 will. Only content encodings "x-compress" and "x-gzip" are currently handled.
- Transparent uncompression for local files is now working.
- Mail sending from within Mosaic is redone. Notably:
  - `mailCommand` resource is now totally obsolete.
  - `sendmailCommand` resource is now expected to point to your system's `sendmail` binary; default is `/usr/lib/sendmail`. Assumption is made that this program accepts command-line arguments specifying addresses to which message should be mailed, and accepts other headers and message text from stdin.
  - Mailed messages are now MIME-compliant, including use of proper content-types.
  - Additional header `X-URL` is used to indicate the URL of a mailed document to the recipient.
  - A `BASE` directive is added to mailed HTML documents to allow inlined images and relative hyperlinks to work on the other end.
- Mosaic 1.2's multiline FTP response fixes (courtesy John Ockerbloom) merged in, and tweaks made.
- Added support for freeWAIS 0.202's URL type in native WAIS code.
- Added support for "204 NoResponse" responses in HTTP/1.0. When such a response is received, Mosaic will not go to a new document or an error message but will completely disregard the results of the connection.
- Status line now displays "xx of yy bytes" when talking to an HTTP/1.0 server that tells it content-length. (For small transfers this may not happen, which is to be expected, as header and entire data block transfer will be very close together.)
- Worked around BadWindow crash under Ultrix with Edit Hotlist window.
- Worked around BadWindow crash under Ultrix with `ISINDEX` forms and text entry areas.
- Glitch with formatting long lines in some cases fixed.
- Fixed rare coredump opportunity in `SELECT`/`OPTION` handling.
- Fixed rare uninitialized memory read in widget selection code.
- Fixed another coredump opportunity in inlined image loading.
- Fixed coredump opportunity in client-side authentication code with long (`>48` character) realm names.
- Mosaic no longer tries to pick up final reply from FTP servers, to thwart those servers that don't seem to be responding to the final reply read. Also should make FTP performance a little better. This may be an evil thing to do (since Mosaic may now tear down the socket before the FTP server has finished writing to it); I'm not sure.
- Rob says: "It appears on first glance that Mosaic 2.0 is ignoring anchors in redirected URLs." He was right, and it's now fixed.
- Made a few fixes in PostScript printing code: corrected header generation, and fixed width handling (thanks to Gustaf Neumann).
- Tweaked reloading code to avoid strange error message.
- Mosaic now assumes that text documents beginning with string "<BASE" or "<base" are HTML -- this makes it easy to use Mosaic as a metamail viewer for HTML documents mailed from this version of Mosaic.
- Merged in donated fixes for 6-bit and 16-bit displays. These aren't guaranteed to work as we have no way to test them.
- Fixed missing closing `ADDRESS` tag in news articles.
- Fixed condition in WAIS source parser that caused it to lose track of its state if escapted characters were inside quotes (thanks to Larry Masinter).
- Fixed FTP code to allow `ftp://username:password@host/` URLs (thanks to Larry Masinter).
- This version of Mosaic supports the GIF89 transparent color extension. You can create GIFs with a transparent background color with the latest beta of `netpbm` and its `ppmtogif` filter (you can FTP that from `ftp.cs.ubc.ca` in `/ftp/archive/netpbm` if you're desperate).
- Merged in SOCKS modifications from Ying-Da Lee (ylee@syl.dl.nec.com); for the version of SOCKS needed to compile with SOCKS support enabled, see here; note that SOCKS and the SOCKS code now in Mosaic are NOT supported by NCSA.
- Fixed memory problem with `trackFullURLs` set to `false` (that option still doesn't work in all cases, but at least it does something reasonable now).
- Tweaks for compilation on various platforms.

See also an extensive list of recent technical changes and the unofficial Mosaic for X "to-do" list.

## Other Information

Information on other versions of NCSA Mosaic is here.

General information on NCSA Mosaic is available here.