It seems like whomever you need to share information with never seems to have the same program you use. There was a time when Personal Ancestral File (PAF) was pervasive. But with the de-emphasis on the program, there are dozens of different options. Your first door of opportunity in sharing files is to see what formats are supported by your own program. If you still use PAF your choices are really limited, you can import a GEDCOM or another PAF file. If you are exporting a file, you have a few more choices. Here is the Export Screen from PAF 5.2.18, the latest version:
The choices include various versions of PAF, the Ancestral File which is no longer in existence, the Pedigree Resource File which is still sort-of in existence, TempleReady which is no longer in existence, PAF for a Palm OS which is still in existence (2010), and GEDCOM 5.5 which is still supported by most other genealogy programs.
From a developers standpoint, there is almost no incentive to support your competitor's file format. Why would you want to make it easy for someone to switch programs? In genealogy, the issue of file sharing arises because of the need to share the information without re-entering massive amounts of data.
The current version of Ancestral Quest, the successor to PAF, has the similar options for importing files as PAF, GEDCOM or an Ancestral Quest file. However, the program supports exports to Heritage Family Tree Deluxe, Family Tree Maker, various versions of PAF and various older versions of Ancestral Quest. The version of Family Tree Maker supported is not specified.
If you use a program like RootsMagic 4, you have a few more options for importing a file. Here is the Import screen from the latest version of RootsMagic:
Again, if your particular program is not listed, you option is to create a GEDCOM file and import the information in that manner. Your options for export are limited to GEDCOM only. Even though Family Tree Maker is specified as supported, the import will only work with versions 2006 and earlier and the current version is 2011.
Legacy Family Tree will import from another Legacy file or from PAF directly, all other program files would have to be exported to a GEDCOM file. Your choice for export are also limited to Legacy, PAF or a GEDCOM.
I have version 2010 of Family Tree Maker for the PC, so I can only write about that version, but its import function supports previous versions of Family Tree Maker, Personal Ancestral File, The Master Genealogist, Legacy Family Tree, Personal Ancestral File and GEDCOM. The export function supports some previous versions of Family Tree Maker and GEDCOM.
On the Mac side of things, Family Tree Maker for the Mac has fewer options than the PC version, it is not clear whether or not the Mac files will also import into the PC version or PC to Mac. But when I tried to open a PC file with my Family Tree Maker for the Mac, it did not recognize the file.
In the Linux tech community there is some discussion and use of the open source program, Gramps, This free program is limited in its use in both Windows environments and on Mac OS X. However, I note that Gramps supports both import and export of GEDCOM files.
I could go on and on, but the point is this. There are few options for sharing files directly between different genealogy programs. Family Tree Maker for the PC and RootsMagic seem to have the most options, but all of the programs support a GEDCOM import. That may seem like good news until you realize that if you use GEDCOM to transfer data between genealogy programs you will very likely lose data in the process, even if you are transferring between the same programs i.e. from PAF to PAF.
Here is the bad news. There is presently no solution which is the best reason for the project to build a better GEDCOM and improve the chances of transferring information. If you would like more information please see BetterGedcom.
There are a number of options for sharing the information without actually sharing the file itself. RootsMagic will create a sharable CD with all of your file information, but the information is read only meaning the file cannot be edited by the recipient.
If you would like to get an idea of the complexity of file sharing options and have a word processing program like Microsoft Word or OpenOffice, when you go to save a file, check out the different possible formats for saving. Presently, there does not appear to be any major movement in the computer world to solve the file compatibility issues.