The Sitecore Item Merge Tool
The goal of TDS has always been to make it easier for developers to do what they do best – build cool stuff. The Sitecore Item Merge Tool (SIMT) was introduced in Team Development for Sitecore (TDS) 5.1, and was designed to help developers increase their productivity by safely merging the .item files. It’s a fantastic addition, one that developed out of internal and external user feedback, and improves productivity by leaps and bounds.
How It Works

The SIMT works to protect developers against the corruption of .item files by allowing them to select each field as a whole during the merge, which produces an appropriately formatted .item file.

.item files have a unique structure; each definition of a field’s contents can span multiple lines of text. Because of this format it’s easy for incorrect merges to take place in source control; the files can easily become corrupted. Once they’re corrupted they are no longer compatible with a Sitecore serialization engine and therefore they aren’t deployable.

Enter the Sitecore Item Merge Tool. Because things that break during a build are rarely obvious and never small, the SIMT eliminates hurdles and improves developer efficiency by stopping problems before they start. It’s ideal for any development team with more than a single member, especially if there’s more than one developer working on a single item. If, for example, two people have changed the same item and the item is run through regular merge tools, the files become corrupted and all is darkness and gloom. The more people there are working on a single item, the greater the chances that a bad merge could occur. The SIMT helps teams merge safely, removing that potential headache entirely.

See It in Action
sitecore .item file

Always merge all your Sitecore .item files safely.