Recoll is a personal full text search tool for Unix/Linux.

Recoll is a desktop search tool that provides efficient full text search (from single-word to arbitrarily complex boolean searches) in a friendly GUI, with minimum technical sophistication and few mandatory external dependencies. It runs under many Unix-like operating systems, and is mostly independent of the desktop environment.

Recoll was designed not to require a permanent daemon. It updates its index at designed intervals (for example through Cron tasks). Only if desired, the indexing task can run as a file-system monitoring daemon for real-time index updates.

The Recoll document conversion and text extraction architecture makes it extremely easy to write new filters, and many document types are supported.

Features.
    Qt GUI.
    Xapian backend.
    Indexes the contents of many document types: text, HTML, E-Mail stores of all kinds, OpenOffice, Microsoft Office and Office Open XML, AbiWord, KWord, Gaim, Lyx, Scribus, PDF, WordPerfect, PostScript, RTF, TeX, DVI, DjVu, MP3 and other audio file formats, JPEG and other image file formats.[4]
    Recursively processes embedded documents (E-Mail attachments, Zip archives) to arbitrary depths.
    Powerful query facilities, with boolean searches, wildcards, phrases, proximity, filter on file types and directory tree. GUI Boolean search build tool.
    Xesam query language support
    Word stemming is performed at query time (can switch stemming language after indexing).
    Multiple indexes selectable at query time (ie: personal + system indexes).
    Natively based on Unicode. Supports many languages and input character sets, including good support for east asian texts (CJK).
    MD5 document hashes for the elimination of duplicates in result lists.
    Batch and real-time indexing modes.
    Python API.
    Kicker (KDE) applet for easy launching.
    Easy installation. No database daemon, web server or exotic language necessary.

The current Recoll version is 1.17.3 (Release notes).

Installing a binary copy.
There are three types of binary Recoll installations:
    Through your system normal software distribution framework (ie, Debian/Ubuntu apt, FreeBSD ports, etc.).
    From a package downloaded from the Recoll web site.
    From a prebuilt tree downloaded from the Recoll web site.
In all cases, the strict software dependancies (ie on Xapian or iconv) will be automatically satisfied, you should not have to worry about them.

You will only have to check or install supporting applications for the file types that you want to index beyond those that are natively processed by Recoll (text, HTML, email files, and a few others).
You should also maybe have a look at the configuration section (but this may not be necessary for a quick test with default parameters). Most parameters can be more conveniently set from the GUI interface.

5.1.1. Installing through a package system
If you use a BSD-type port system or a prebuilt package (DEB, RPM, manually or through the system software configuration utility), just follow the usual procedure for your system.

5.1.2. Installing a prebuilt Recoll
The unpackaged binary versions on the Recoll web site are just compressed tar files of a build tree, where only the useful parts were kept (executables and sample configuration).
The executable binary files are built with a static link to libxapian and libiconv, to make installation easier (no dependencies).
After extracting the tar file, you can proceed with installation as if you had built the package from source (that is, just type make install). The binary trees are built for installation to /usr/local.

Screenshots.