Programmatically tell whether a webpart that has been deployed is a native one that ships with MOSS, or one that was custom developed?

Question

I have a SharePoint 2007 MOSS instance, and I'm on a fact-finding mission. There have been multiple developers, developing multiple webparts and deploying them (using VS2005/2008 SharePoint Extensions).

I thought maybe I could look at the fields in the "Web Part Gallery" list in my site, and look by "Modified by", but it looks like a developer's name is on some of the out-of-the-box webparts somehow, and on ones I know are custom developed, they say "System Account" - so looking at that field in this list is a no go.

I thought then maybe I could look at the "Group" to which each webpart was assigned but it looks like they were arbitrarily assigned to many different groups inconsistently - so using that piece of information is a no go.

Here is my code I have for just looping through and getting the names of all the webparts. Is there any property I can access on the list items of webparts that would tell me whether it's a custom developed webpart? Any way to distinguish the custom webparts from the out-of-the-box ones? Is there another way to do this?

        #region Misc Site Collection Methods
        public static List<string> GetAllWebParts(string connectedSPInstanceUrl)
        {
            List<string> lstWebParts = new List<string>();

            try
            {
                using (SPSite site = new SPSite(connectedSPInstanceUrl))
                {
                    using (SPWeb web = site.OpenWeb())
                    {
                        SPList list = web.Lists["Web Part Gallery"];
                        foreach (SPListItem item in list.Items)
                        {
                            lstWebParts.Add(item.Name);
                        }
                    }
                }
            }
            catch (Exception ex)
            {
                lstWebParts.Add("Error");
                lstWebParts.Add("Message: " + ex.Message);
                lstWebParts.Add("Inner Exception: " + ex.InnerException.ToString());
                lstWebParts.Add("Stack Trace: " + ex.StackTrace);
            }

            return lstWebParts;
        }
        #endregion

Answer 1

Have you tried exporting the webparts? Click on the arrow on the top right of the webpart and click on export. It will be exported as an XML file. Look for the metadata tag. e.g.:

<metaData>
  <type name="Microsoft.SharePoint.Portal.WebControls.KPIListWebPart, Microsoft.SharePoint.Portal, Version=12.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c" />
  <importErrorMessage />
</metaData>

The type attribute will give you the assembly information. If it is a custom webpart, the assembly name should mostly be something other than Microsoft.Sharepoint