Ifilter

SharePoint Search
File types and IFilters reference (SharePoint Server 2010)
http://technet.microsoft.com/en-us/library/gg405170.aspx
How to install and configure Adobe PDF iFilter 9 for SharePoint 2010
http://support.microsoft.com/kb/2293357
Microsoft Office 2010 Filter Packs
http://www.microsoft.com/en-us/download/details.aspx?id=17062

List displayed using regedit

FS4SP - FAST Search for SharePoint
File types and IFilters reference (FS4SP)
http://technet.microsoft.com/en-us/library/gg471168.aspx
Enable Advanced Filter Pack for FS4SP
http://technet.microsoft.com/en-us/library/ff383314.aspx
Use Microsoft FAST Search Server 2010 for SharePoint Command Shell

ifilter2html.exe -l to list


More References
http://blogs.msdn.com/b/ifilter/
http://www.ableblue.com/blog/archive/2011/09/28/troubleshooting-ifilters-and-crawled-properties/
http://www.ableblue.com/blog/archive/2012/01/03/troubleshooting-sharepoint-search-ifilter-registration/
http://www.directsharepoint.com/2011/11/powershell-script-for-installing-pdf.html
http://www.nirsoft.net/utils/search_filter_view.html
http://msdn.microsoft.com/en-us/library/hh694268.aspx#odc_sp14_ta_HowToBuildAnIFilter_PackagingAndDeployingAnIFilter