Is the Panamanian government in charge of the canal, or is it a private organization? Are any other countries involved?

The Panama Canal is under the control of the Panama government, and administered by the Panama Canal Authority (ACP), a semi-autonomous government agency.  The operation of the shipping container ports at either end of the Canal was contracted out to a Hong-Kong based firm, Hutchison Whampoa.  The Canal used to be under US control, but in December 1999 the US relinquished control of this valuable shipping and trade hub, and withdrew their presence from the country.