Recoll downloads
You will probably need to have a look at the installation manual for building and/or installation instructions.
For building from source, you will need a xapian-core installation. You will find source and binary packages on the xapian download page
You need qt 3.3 in all cases
Recoll relies on external packages for some of its functionality (ie: for many of the non text file types). These are not listed as strict dependencies, because the base application can be sufficient in some cases, but you should have a look at the list to decide what you may want to install.
Source
Current version: 1.5.11: recoll-1.5.11.tar.gz. See the known bugs and issues and changes.
Older recoll releases: 1.5.6. 1.4.3. 1.3.3. 1.2.3. 1.1.0. 1.0.16.
RPMS
The executables inside the binary rpms have a static link to xapian, there is no dependency except Qt 3.3. Of course you need xapian-core installed to use the source rpm.
Fedora Core 5 RPM: recoll-1.5.11-1.i386.rpm. Source: recoll-1.5.11-1.src.rpm
Mandriva 2006 (also works on 2005 and 2007) RPM: recoll-1.5.11-0.1.20060mdk.i586.rpm. Source: recoll-1.5.11-0.1.20060mdk.src.rpm
Suse 10.1 It seems that the binaries in previous set of rpms, which were built with the xapian packages from opensuse had a serious tendancy to segfault on exceptions. I hope that the current ones, with a local xapian build will work better. If there are still problems, please compile from source. RPM: recoll-1.5.11-0.i586.rpm. Source: recoll-1.5.11-0.src.rpm
Binary bundles
These are just prebuilt trees (without the source files). The executables were built with xapian 0.9.[6-9] and libiconv 1.9.2 (where relevant) as static libraries. They depend on qt 3.3. For Solaris, you should be able to find a qt package here.
The installation instructions are there.
FreeBSD 5.5 i386: recoll-1.5.11-FreeBSD-5.5-RELEASE.tgz
Solaris 8 sparc. recoll-1.5.4-SunOS-5.8.tgz.
FreeBSD ports
There are ports for both xapian-core and recoll in the standard tree, you may just need to update your ports (cvsup), or you can get the ports from the FreeBSD site: xapian port recoll port.